//exercise 4.1
package fourthchapterexercise1;
import java.util.Scanner;
public class first {
public static void main(String[] args) {
// TODO Auto-generated method stub
int integer=0,sum=0,positive=0,negative=0;
Scanner in=new Scanner(System.in);
System.out.println("Enter an int value,the program exits if the input is 0:");
while(true){
integer=in.nextInt();
if(integer==0)
break;
else if(integer>0)
positive++;
else
negative++;
sum=sum+integer;
}
double average=(double)sum/(positive+negative);
System.out.println("The number of positives is "+positive);
System.out.println("The number of negatives is "+negative);
System.out.println("The total is "+sum);
System.out.println("The average is "+average);
}
}
//exercise 4.2
package fourthchapterexercise1;
import java.util.Scanner;
public class second {
public static void main(String[] args) {
// TODO Auto-generated method stub
final int NUMBER_OF_QUESTIONS=10;
int correctCount=0;
int count=0;
long startTime=System.currentTimeMillis();
String output="";
Scanner in=new Scanner(System.in);
//The main program
while (count<NUMBER_OF_QUESTIONS){
//0-15 random number
int number1=(int)(Math.random()*15+1);
int number2=(int)(Math.random()*15+1);
//input expression
System.out.print("What is "+number1+" + "+number2+"? ");
//get answer
int answer=in.nextInt();
//judge answer
if(number1+number2==answer){
System.out.println("You are correct!");
correctCount++;
}
else
System.out.println("Your answer is wrong.\n"+number1+" + "+number2+" sh"
+ "ould be "+(number1+number2));
//count
count++;
output +="\n"+number1+" + "+number2+"="+answer+((number1+number2==answer)?" cor"
+ "rect":" wrong");
}
long endTime=System.currentTimeMillis();
long testTime=endTime-startTime;
System.out.println("Correct count is "+correctCount+"\nTest time is "+testTime/1000+" seco"
+ "nds\n"+output);
}
}
//exercise 4.3
package fourthchapterexercise1;
public class third {
public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.println("千克\t\t英镑");
for(int i=0;i<100;i++){
System.out.println(2*i+1+"\t\t"+(2*i+1)*2.2);
}
}
}
//exercise 4.4
package fourthchapterexercise1;
public class fourth {
public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.println("英里\t\t千米");
for(int i=1;i<=10;i++){
System.out.println(i+"\t\t"+i*1.609);
}
}
}
//exercise 4.5
package fourthchapterexercise1;
public class fifth {
public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.println("千克\t\t镑\t\t磅\t\t千克");
int pound=20;
for(int i=0;i<100;i++){
System.out.println(2*i+1+"\t\t"+(int)((2*i+1)*2.2*100)/100.0+"\t"
+ "\t"+pound+"\t\t"+(int)(pound/2.2*100)/100.0);
pound+=5;
}
}
}
//exercise 4.6
package fourthchapterexercise1;
public class sixth {
public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.println("英里\t\t千米\t\t英里\t\t千米");
int pound=20;
for(int i=0;i<10;i++){
System.out.println(i+"\t\t"+(int)(i*1.609*1000)/1000.0+"\t"
+ "\t"+pound+"\t\t"+(int)(pound/1.609*1000)/1000.0);
pound+=5;
}
}
}
//exercise 4.7
package fourthchapterexercise1;
public class seventh {
public static void main(String[] args) {
// TODO Auto-generated method stub
double tuition=10000;
for(int i=0;i<10;i++){
tuition *= (1+0.05);
}
System.out.println("after ten year,tuition is "+tuition);
double sum=0;
for(int i=0;i<4;i++){
sum += tuition;
tuition *= (1+0.05);
}
System.out.println("tuition of four year is "+sum);
}
}
//exercise 4.8
package fourthchapterexercise1;
import java.util.Scanner;
public class eighth {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in=new Scanner(System.in);
System.out.print("please input number of students is ");
int number =in.nextInt();
String maxname=null;
int max=0;
for(int i=0;i<number;i++){
System.out.print("please input student‘s name and score:");
String name =in.next();
int score=in.nextInt();
if(score>max)
maxname=name;
}
System.out.print("The most high score students name is :"+maxname);
}
}
//exercise 4.9
package fourthchapterexercise1;
import java.util.Scanner;
public class ninth {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in=new Scanner(System.in);
System.out.print("please input number of students is: ");
int number =in.nextInt();
String maxname=null,secondname=null;
int max=0;
int secondhigh=0;
for(int i=0;i<number;i++){
System.out.print("please input student‘s name and score:");
String name =in.next();
int score=in.nextInt();
if(score>max){
maxname=name;
max=score;
}
if(score>secondhigh&&score!=max){
secondname=name;
secondhigh=score;
}
}
System.out.println("The most high score students name is :"+maxname);
System.out.println("The second high score students name is :"+secondname);
}
}
//exercise 4.10
package fourthchapterexercise1;
import java.util.Scanner;
public class tenth {
public static void main(String[] args) {
// TODO Auto-generated method stub
int count=0;
for (int i=100;i<=1000;i++){
if(i%5==0&&i%6==0){
System.out.print("\t"+i);
count++;
if(count%10==0)
System.out.println();
}
}
}
}
//exercise 4.11
package fourthchapterexercise2;
public class first {
public static void main(String[] args) {
// TODO Auto-generated method stub
int count=0;
for (int i=100;i<=200;i++){
if(i%5==0^i%6==0){
System.out.print("\t"+i);
count++;
if(count%10==0)
System.out.println();
}
}
}
}
//exercise 4.12
package fourthchapterexercise2;
public class second {
public static void main(String[] args) {
// TODO Auto-generated method stub
int n=1;
while(true){
if(n*n>12000){
System.out.println("The smallest integer is "+n);
break;
}
n++;
}
}
}
//exercise 4.13
package fourthchapterexercise2;
public class third {
public static void main(String[] args) {
// TODO Auto-generated method stub
int n=1;
while(true){
if(n*n*n>12000){
System.out.println("The smallest integer is "+(n-1));
break;
}
n++;
}
}
}
//exercise 4.14
package fourthchapterexercise2;
public class fourth {
public static void main(String[] args) {
// TODO Auto-generated method stub
int startascii=33;
int count=0;
while(startascii<=126){
char output=(char)startascii;
count++;
System.out.print("\t"+output);
if(count%10==0)
System.out.println();
startascii++;
}
}
}
//exercise 4.15
package fourthchapterexercise2;
import java.util.Scanner;
public class fifth {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in=new Scanner(System.in);
System.out.print("please input two integer n1 and n2 :");
int n1=in.nextInt();
int n2=in.nextInt();
int min;
if(n1>n2)
min=n2;
else
min=n1;
while(true){
if(n1%min==0&&n2%min==0){
System.out.println("The greatest common divisor is "+min);
break;
}
min--;
}
}
}
//exercise 4.16
package fourthchapterexercise2;
import java.util.Scanner;
public class sixth {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in=new Scanner(System.in);
System.out.print("please input integer:");
int integer=in.nextInt();
System.out.print("The factor is :");
while(true){
for(int i=2;i<=integer;i++){
if(integer%i==0){
System.out.print(i);
integer=integer/i;
if(integer==1)
System.out.print(".");
else
System.out.print(",");
break;
}
}
if(integer==1)
break;
}
}
}
//exercise 4.17
package fourthchapterexercise2;
import java.util.Scanner;
public class seventh {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in=new Scanner(System.in);
System.out.print("please input integer (0-15):");
int input =in.nextInt();
for(int i=1;i<=input;i++){
for(int j=1;j<=input-i;j++){
if(j==input-i){
System.out.print("\t");
break;
}
System.out.print("\t ");
}
for(int k=i;k>0;k--){
if(k==1){
System.out.print(k);
break;
}
System.out.print(k+"\t");
}
for(int j=2;j<=i;j++){
System.out.print("\t"+j);
}
System.out.println();
}
}
}
//exercise 4.18
package fourthchapterexercise2;
public class eighth {
public static void main(String[] args) {
// TODO Auto-generated method stub
//pattern 1
for(int i=1;i<=6;i++){
for(int j=1;j<=i;j++){
System.out.print(j+"\t");
}
System.out.println();
}
System.out.println();
System.out.println();
//pattern 2
for(int i=1;i<=6;i++){
for(int j=1;j<=7-i;j++){
System.out.print(j+"\t");
}
System.out.println();
}
System.out.println();
System.out.println();
//pattern 3
for(int i=1;i<=6;i++){
for(int j=1;j<=6-i;j++){
System.out.print(" \t");
}
for(int k=i;k>=1;k--){
System.out.print(k+"\t");
}
System.out.println();
}
System.out.println();
System.out.println();
//pattern 4
for(int i=1;i<=6;i++){
for(int k=2;k<=i;k++){
System.out.print(" \t");
}
for(int j=1;j<=7-i;j++){
System.out.print(j+"\t");
}
System.out.println();
}
}
}
//exercise 4.19
package fourthchapterexercise2;
public class ninth {
public static void main(String[] args) {
// TODO Auto-generated method stub
int integer;
for(int i=1;i<=8;i++){
for(int j=1;j<=8-i;j++){
System.out.print(" ");
}
for(int j=1;j<=i;j++){
integer=(int)Math.pow(2, j-1);
System.out.printf("%4d",integer);
}
for(int k=i-1;k>=1;k--){
integer=(int)Math.pow(2, k-1);
System.out.printf("%4d",integer);
}
System.out.println();
}
}
}
//exercise 4-20
package fourthchapterexercise3;
public class first {
public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.println("prime of 2 to 1000 is:");
int count=0;
for(int i=2;i<=1000;i++){
boolean isprime=true;
for(int j=2;j<=i/2;j++){
if(i%j==0){
isprime=false;
break;
}
}
if(isprime){
count++;
System.out.printf("%4d",i);
}
if(count%8==0&&isprime)
System.out.println();
}
}
}
//exercise 4.21
package fourthchapterexercise3;
import java.util.Scanner;
//This function is not a rigorous
//The corrected
public class second {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in=new Scanner(System.in);
System.out.print("please input loan amount:");
int loanamount=in.nextInt();
System.out.print("Number of years:");
int numberofyears=in.nextInt();
double interestrate=0.05;
int count;
System.out.println("Inerest Rate Monthly payment Total Payment");
//computational
for(count=0;count<=24;count++){
double monthlyinterestrate=interestrate/12;
//The monthly payment
double monthlypayment=(loanamount*monthlyinterestrate)/
(1-1/Math.pow(1+monthlyinterestrate,numberofyears*12));
//total payment
double totalpayment=monthlypayment*12*numberofyears;
System.out.println((int)(interestrate*100000)/1000.0+"%\t\t "+
(int)(monthlypayment*100)/100.0+"0\t\t"+(int)(totalpayment*100)/100.0);
interestrate +=0.00125;
}
}
}
//exercise 4.22
package fourthchapterexercise3;
import java.util.Scanner;
public class third {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in=new Scanner(System.in);
System.out.print("Loan Amount:");
int loanamount=in.nextInt();
System.out.print("Number of Years:");
int numberofyears=in.nextInt();
System.out.print("Annual Interest rate:");
double annualinterestrate=in.nextDouble();
double monthlyinterestrate=annualinterestrate/12;
double monthlypayment=(loanamount*monthlyinterestrate)/
(1-1/Math.pow(1+monthlyinterestrate,numberofyears*12));
double totalpayment=monthlypayment*12*numberofyears;
System.out.println("\nMonthly Payment:"+monthlypayment);
System.out.println("Total Payment"+totalpayment);
System.out.println();
double interest=0,principal;
double balance=loanamount;
System.out.println("Payment\t\tInterest\t\t Principal\t\t Balance");
for(int i=1;i<=numberofyears*12;i++){
interest=monthlyinterestrate*balance;
principal=monthlypayment-interest;
balance=balance-principal;
System.out.println(i+"\t\t"+interest+"\t\t"+principal+"\t\t"+balance);
}
}
}
//exercise 4.23
package fourthchapterexercise3;
public class fourth {
public static void main(String[] args) {
// TODO Auto-generated method stub
double sum=0;
for(int i=1;i<=5000;i++){
sum += 1.0/i;
}
System.out.println("This is from left to right:"+sum);
sum=0;
for(int i=5000;i>=1;i--){
sum += 1.0/i;
}
System.out.println("This is from right to left:"+sum);
}
}
//exercise 4.24
package fourthchapterexercise3;
public class fifth {
public static void main(String[] args) {
// TODO Auto-generated method stub
double sum=0;
double molecular=1;
double denominator=3;
for(int i=1;i<=49;i++){
sum += molecular/denominator;
molecular += 2;
denominator += 2;
}
System.out.println("result is "+sum);
}
}
//exercise 4.25
package fourthchapterexercise3;
public class sixth {
public static void main(String[] args) {
// TODO Auto-generated method stub
for(int i=10000;i<=100000;i += 10000){
double pi=0,sum=0;
for (int j=0;j<=i;j++){
sum =sum+Math.pow(-1,j)*(1.0/(2*j+1));
}
pi=4*sum;
System.out.print("when i="+i+",pi="+pi+"\n");
}
}
}
//exercise 4.26
package fourthchapterexercise3;
//The arithmetic is not good enough
public class seventh {
public static void main(String[] args) {
// TODO Auto-generated method stub
for(int i=10000;i<=100000;i +=10000){
double sum=1;
double generaltype=1;
for(int j=1;j<=i;j++){
for(int k=1;k<=j;k++){
generaltype *= 1.0/k;
}
sum += generaltype;
}
System.out.println("When i="+i+",e="+sum);
}
}
}
//exercise 4.27
package fourthchapterexercise3;
public class eighth {
public static void main(String[] args) {
// TODO Auto-generated method stub
int count=0;
System.out.println("A leap year all in twenty-first Century is:");
for(int year=2001;year<=2100;year++){
if(year%4==0&&year%100!=0||year%400==0){
System.out.print(year+" ");
count++;
if(count%10==0)
System.out.println();
}
}
}
}
//exercise 4.28
package fourthchapterexercise3;
import java.util.Scanner;
public class ninth {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in=new Scanner(System.in);
System.out.print("please input year and days of week:");
int year=in.nextInt();
int january=in.nextInt();
//The calculation of the first day of the month is the day of the week
int february=(january+31)%7;
int march=(february+28)%7;
if(year%4==0&&year%100!=0||year%400==0)
march=(february+29)%7;
int april=(march+31)%7;
int may=(april+30)%7;
int june=(may+31)%7;
int july=(june+30)%7;
int august=(july+31)%7;
int september=(august+31)%7;
int october=(september+30)%7;
int november=(october+31)%7;
int december=(november+30)%7;
//matching week
String week=null;
switch(january){
case 0:
week="Sunday";
break;
case 1:
week="Monday";
break;
case 2:
week="Tuesday";
break;
case 3:
week="Wednesday";
break;
case 4:
week="Thursday";
break;
case 5:
week="Friday";
break;
case 6:
week="Saterday";
break;
default:
break;
}
System.out.println("January 1, "+year+" is "+week);
switch(february){
case 0:
week="Sunday";
break;
case 1:
week="Monday";
break;
case 2:
week="Tuesday";
break;
case 3:
week="Wednesday";
break;
case 4:
week="Thursday";
break;
case 5:
week="Friday";
break;
case 6:
week="Saterday";
break;
default:
break;
}
System.out.println("february 1, "+year+" is "+week);
switch(march){
case 0:
week="Sunday";
break;
case 1:
week="Monday";
break;
case 2:
week="Tuesday";
break;
case 3:
week="Wednesday";
break;
case 4:
week="Thursday";
break;
case 5:
week="Friday";
break;
case 6:
week="Saterday";
break;
default:
break;
}
System.out.println("march 1, "+year+" is "+week);
switch(april){
case 0:
week="Sunday";
break;
case 1:
week="Monday";
break;
case 2:
week="Tuesday";
break;
case 3:
week="Wednesday";
break;
case 4:
week="Thursday";
break;
case 5:
week="Friday";
break;
case 6:
week="Saterday";
break;
default:
break;
}
System.out.println("april 1, "+year+" is "+week);
switch(may){
case 0:
week="Sunday";
break;
case 1:
week="Monday";
break;
case 2:
week="Tuesday";
break;
case 3:
week="Wednesday";
break;
case 4:
week="Thursday";
break;
case 5:
week="Friday";
break;
case 6:
week="Saterday";
break;
default:
break;
}
System.out.println("may 1, "+year+" is "+week);
switch(june){
case 0:
week="Sunday";
break;
case 1:
week="Monday";
break;
case 2:
week="Tuesday";
break;
case 3:
week="Wednesday";
break;
case 4:
week="Thursday";
break;
case 5:
week="Friday";
break;
case 6:
week="Saterday";
break;
default:
break;
}
System.out.println("june 1, "+year+" is "+week);
switch(july){
case 0:
week="Sunday";
break;
case 1:
week="Monday";
break;
case 2:
week="Tuesday";
break;
case 3:
week="Wednesday";
break;
case 4:
week="Thursday";
break;
case 5:
week="Friday";
break;
case 6:
week="Saterday";
break;
default:
break;
}
System.out.println("july 1, "+year+" is "+week);
switch(august){
case 0:
week="Sunday";
break;
case 1:
week="Monday";
break;
case 2:
week="Tuesday";
break;
case 3:
week="Wednesday";
break;
case 4:
week="Thursday";
break;
case 5:
week="Friday";
break;
case 6:
week="Saterday";
break;
default:
break;
}
System.out.println("august 1, "+year+" is "+week);
switch(september){
case 0:
week="Sunday";
break;
case 1:
week="Monday";
break;
case 2:
week="Tuesday";
break;
case 3:
week="Wednesday";
break;
case 4:
week="Thursday";
break;
case 5:
week="Friday";
break;
case 6:
week="Saterday";
break;
default:
break;
}
System.out.println("september 1, "+year+" is "+week);
switch(october){
case 0:
week="Sunday";
break;
case 1:
week="Monday";
break;
case 2:
week="Tuesday";
break;
case 3:
week="Wednesday";
break;
case 4:
week="Thursday";
break;
case 5:
week="Friday";
break;
case 6:
week="Saterday";
break;
default:
break;
}
System.out.println("october 1, "+year+" is "+week);
switch(november){
case 0:
week="Sunday";
break;
case 1:
week="Monday";
break;
case 2:
week="Tuesday";
break;
case 3:
week="Wednesday";
break;
case 4:
week="Thursday";
break;
case 5:
week="Friday";
break;
case 6:
week="Saterday";
break;
default:
break;
}
System.out.println("november 1, "+year+" is "+week);
switch(december){
case 0:
week="Sunday";
break;
case 1:
week="Monday";
break;
case 2:
week="Tuesday";
break;
case 3:
week="Wednesday";
break;
case 4:
week="Thursday";
break;
case 5:
week="Friday";
break;
case 6:
week="Saterday";
break;
default:
break;
}
System.out.println("december 1, "+year+" is "+week);
}
}
//exercise 4.29
package fourthchapterexercise3;
import java.util.Scanner;
public class tenth {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in=new Scanner(System.in);
System.out.print("please input year and days of week:");
int year=in.nextInt();
int january=in.nextInt();
//The calculation of the first day of the month is the day of the week
int february=(january+31)%7;
int march=(february+28)%7;
if(year%4==0&&year%100!=0||year%400==0)
march=(february+29)%7;
int april=(march+31)%7;
int may=(april+30)%7;
int june=(may+31)%7;
int july=(june+30)%7;
int august=(july+31)%7;
int september=(august+31)%7;
int october=(september+30)%7;
int november=(october+31)%7;
int december=(november+30)%7;
//January
System.out.println("\t\t January"+year+" \t");
System.out.println("----------------------------------------------------");
System.out.println("Sun\tMon\tTue\tWed\tThu\tFri\tSat");
int count=1;
for(int i=0;i<january;i++){
System.out.print(" \t");
}
//wrap
int temp=january;
//A month has 31 days
for(count=1;count<=31;count++){
if(temp%7==0){
System.out.println();
temp=0;
}
System.out.printf("%3d\t",count);
temp++;
}
System.out.println("\n");
//February
System.out.println("\t\t February"+year+" \t");
System.out.println("----------------------------------------------------");
System.out.println("Sun\tMon\tTue\tWed\tThu\tFri\tSat");
count=1;
for(int i=0;i<february;i++){
System.out.print(" \t");
}
//wrap
temp=february;
//A month has 28 or 29 days
int feb=28;
if(year%4==0&&year%100!=0||year%400==0)
feb=29;
for(count=1;count<=feb;count++){
if(temp%7==0){
System.out.println();
temp=0;
}
System.out.printf("%3d\t",count);
temp++;
}
System.out.println("\n");
//March
System.out.println("\t\t March"+year+" \t");
System.out.println("----------------------------------------------------");
System.out.println("Sun\tMon\tTue\tWed\tThu\tFri\tSat");
count=1;
for(int i=0;i<march;i++){
System.out.print(" \t");
}
//wrap
temp=march;
//A month has 31 days
for(count=1;count<=31;count++){
if(temp%7==0){
System.out.println();
temp=0;
}
System.out.printf("%3d\t",count);
temp++;
}
System.out.println("\n");
//April
System.out.println("\t\t April"+year+" \t");
System.out.println("----------------------------------------------------");
System.out.println("Sun\tMon\tTue\tWed\tThu\tFri\tSat");
count=1;
for(int i=0;i<april;i++){
System.out.print(" \t");
}
//wrap
temp=april;
//A month has 30 days
for(count=1;count<=30;count++){
if(temp%7==0){
System.out.println();
temp=0;
}
System.out.printf("%3d\t",count);
temp++;
}
System.out.println("\n");
//May
System.out.println("\t\t May"+year+" \t");
System.out.println("----------------------------------------------------");
System.out.println("Sun\tMon\tTue\tWed\tThu\tFri\tSat");
count=1;
for(int i=0;i<may;i++){
System.out.print(" \t");
}
//wrap
temp=may;
//A month has 31 days
for(count=1;count<=31;count++){
if(temp%7==0){
System.out.println();
temp=0;
}
System.out.printf("%3d\t",count);
temp++;
}
System.out.println("\n");
//June
System.out.println("\t\t June"+year+" \t");
System.out.println("----------------------------------------------------");
System.out.println("Sun\tMon\tTue\tWed\tThu\tFri\tSat");
count=1;
for(int i=0;i<june;i++){
System.out.print(" \t");
}
//wrap
temp=june;
//A month has 30 days
for(count=1;count<=30;count++){
if(temp%7==0){
System.out.println();
temp=0;
}
System.out.printf("%3d\t",count);
temp++;
}
System.out.println("\n");
//July
System.out.println("\t\t July"+year+" \t");
System.out.println("----------------------------------------------------");
System.out.println("Sun\tMon\tTue\tWed\tThu\tFri\tSat");
count=1;
for(int i=0;i<july;i++){
System.out.print(" \t");
}
//wrap
temp=july;
//A month has 31 days
for(count=1;count<=31;count++){
if(temp%7==0){
System.out.println();
temp=0;
}
System.out.printf("%3d\t",count);
temp++;
}
System.out.println("\n");
//August
System.out.println("\t\t August"+year+" \t");
System.out.println("----------------------------------------------------");
System.out.println("Sun\tMon\tTue\tWed\tThu\tFri\tSat");
count=1;
for(int i=0;i<august;i++){
System.out.print(" \t");
}
//wrap
temp=august;
//A month has 31 days
for(count=1;count<=31;count++){
if(temp%7==0){
System.out.println();
temp=0;
}
System.out.printf("%3d\t",count);
temp++;
}
System.out.println("\n");
//September
System.out.println("\t\t September"+year+" \t");
System.out.println("----------------------------------------------------");
System.out.println("Sun\tMon\tTue\tWed\tThu\tFri\tSat");
count=1;
for(int i=0;i<september;i++){
System.out.print(" \t");
}
//wrap
temp=september;
//A month has 30 days
for(count=1;count<=30;count++){
if(temp%7==0){
System.out.println();
temp=0;
}
System.out.printf("%3d\t",count);
temp++;
}
System.out.println("\n");
//October
System.out.println("\t\t October"+year+" \t");
System.out.println("----------------------------------------------------");
System.out.println("Sun\tMon\tTue\tWed\tThu\tFri\tSat");
count=1;
for(int i=0;i<october;i++){
System.out.print(" \t");
}
//wrap
temp=october;
//A month has 31 days
for(count=1;count<=31;count++){
if(temp%7==0){
System.out.println();
temp=0;
}
System.out.printf("%3d\t",count);
temp++;
}
System.out.println("\n");
//November
System.out.println("\t\t November"+year+" \t");
System.out.println("----------------------------------------------------");
System.out.println("Sun\tMon\tTue\tWed\tThu\tFri\tSat");
count=1;
for(int i=0;i<november;i++){
System.out.print(" \t");
}
//wrap
temp=november;
//A month has 30 days
for(count=1;count<=30;count++){
if(temp%7==0){
System.out.println();
temp=0;
}
System.out.printf("%3d\t",count);
temp++;
}
System.out.println("\n");
//December
System.out.println("\t\t December"+year+" \t");
System.out.println("----------------------------------------------------");
System.out.println("Sun\tMon\tTue\tWed\tThu\tFri\tSat");
count=1;
for(int i=0;i<december;i++){
System.out.print(" \t");
}
//wrap
temp=december;
//A month has 31 days
for(count=1;count<=31;count++){
if(temp%7==0){
System.out.println();
temp=0;
}
System.out.printf("%3d\t",count);
temp++;
}
System.out.println("\n");
}
}
//exercise 4.30
package fourthchapterexercise4;
import java.util.Scanner;
public class first {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in=new Scanner(System.in);
System.out.print("please input money and annual interest rate and number of month:");
double monthlymoney=in.nextDouble();
double yearlyinterestrate=in.nextDouble();
double numberofmonth=in.nextDouble();
double monthlyinterestrate=yearlyinterestrate/12;
double sum=0;
for(int i=1;i<=numberofmonth;i++){
sum=(monthlymoney+sum)*(1+monthlyinterestrate);
}
System.out.print(numberofmonth+"months later,the money on account of "+sum);
}
}
//exercise 4.31
package fourthchapterexercise4;
import java.util.Scanner;
public class second {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in=new Scanner(System.in);
System.out.print("Enter the initial deposit amount:");
double sum=in.nextDouble();
System.out.print("Enter annual percentage yiekd:");
double yearlyinterestrate=in.nextDouble();
System.out.print("Enter maturityperiod(number if months):");
double numberofmonth=in.nextDouble();
double monthlyinterestrate=yearlyinterestrate/1200;
System.out.println("Month\t\tCD Value");
for(int i=1;i<=numberofmonth;i++){
sum=sum*(1+monthlyinterestrate);
System.out.printf("%5d",i);
System.out.println("\t\t"+sum);
}
}
}
//exercise 4.32
package fourthchapterexercise4;
import java.util.Scanner;
public class third {
public static void main(String[] args) {
// TODO Auto-generated method stub
int lottery=0;
//Generate an integer, the number of two integers is different
while (true){
lottery=(int)(Math.random()*90+10);
int first=lottery/10;
int second=lottery%10;
if(first!=second)
break;
}
Scanner in=new Scanner(System.in);
System.out.print("Enter your lottery pick (two digits):");
int guess =in.nextInt();
//separation lottery digit
int lotteryDigit1=lottery/10;
int lotteryDigit2=lottery%10;
//separation guess digit
int guessDigit1=guess/10;
int guessDigit2=guess%10;
System.out.println("The lottery number is "+lottery);
//judge
if (guess == lottery)
System.out.println("Exact match:you win $10000");
else if(guessDigit2==lotteryDigit1&&guessDigit1==lotteryDigit2)
System.out.println("Match all digits: you win $3000");
else if(guessDigit1==lotteryDigit1
||guessDigit1==lotteryDigit2
||guessDigit2==lotteryDigit1
||guessDigit2==lotteryDigit2)
System.out.println("Match one digit:you win $ 1000");
else
System.out.println("Sorry,no match");
}
}
//exercise 4.33
package fourthchapterexercise4;
public class fourth {
public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.print("Ten thousand the following numbers,perfect number:");
for(int i=1;i<=10000;i++){
int sum=0;
for (int j=1;j<i;j++){
if(i%j==0){
sum=sum+j;
}
}
if(sum==i){
System.out.print(i+" ");
}
}
}
}
//exercise 4.34
package fourthchapterexercise4;
import java.util.Scanner;
public class fifth {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in=new Scanner(System.in);
int computercount=0;
int personcount=0;
while (true){
System.out.print("scissor(0),rock(1),paper(2):");
int input=in.nextInt();
int computer=(int)(Math.random()*3);
if(computer==0&&input==1){
System.out.println("The computer is scissor.You are rock.You win");
personcount++;
computercount=0;
}
else if (computer==0&&input==2){
System.out.println("The computer is scissor.You are paper.You lost.");
computercount++;
personcount=0;
}
else if (computer==0&&input==0){
System.out.println("The computer is scissor.You are scissor.It is a draw.");
computercount=0;
personcount=0;
}
else if (computer==1&&input==0){
System.out.println("The computer is rock.You are scissor.You lost.");
computercount++;
personcount=0;
}
else if (computer==1&&input==1){
System.out.println("The computer is rock.You are rock.It is a draw.");
computercount=0;
personcount=0;
}
else if (computer==1&&input==2){
System.out.println("The computer is rock.You are paper.You win.");
personcount++;
computer=0;
}
else if (computer==2&&input==0){
System.out.println("The computer is paper.You are scissor.You win.");
personcount++;
computercount=0;
}
else if (computer==2&&input==1){
System.out.println("The computer is paper.You are rock.You lost.");
computercount++;
personcount=0;
}
else if (computer==2&&input==2){
System.out.println("The computer is paper.You are paper.It is a draw.");
computercount=0;
personcount=0;
}
if(computercount==2){
System.out.println("The computer won two times.");
break;
}
if(personcount==2){
System.out.println("You won two times.");
break;
}
}
}
}
//exercise 4.35
package fourthchapterexercise4;
public class sixth {
public static void main(String[] args) {
// TODO Auto-generated method stub
double sum=0;
for(int i=1;i<=624;i++){
sum += 1/(Math.pow(i, 0.5)+Math.pow(i+1,0.5));
}
System.out.print("sum is "+sum);
}
}
//exercise 4.37
package fourthchapterexercise4;
import java.util.Scanner;
public class seventh {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in=new Scanner(System.in);
System.out.print("input a integer(Decimal system):");
int integer=in.nextInt();
int count=0;
int temp=integer;
String number="";
//求出字符变成二进制后的长度
while (integer!=0 ){
int remainder=integer%2;
integer /=2;
number =number+(char)(remainder+48);
count++;
}
//转换在数组中
int newcount=count;
char a[]=new char[count];
while (temp!=0 ){
int remainder=temp%2;
temp /=2;
a[count-1]=(char)(remainder+48);
count--;
}
for(int i=0;i<newcount;i++){
System.out.print(a[i]);
}
System.out.print("\n"+number);
}
}
//exercise 4.38
package fourthchapterexercise4;
import java.util.Scanner;
public class eight {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in=new Scanner(System.in);
System.out.print("please input integer(Decimal system):");
int integer=in.nextInt();
String hexadecimal="";
while(integer!=0){
int temp=integer%16;
if(temp<=9&&temp>=0)
hexadecimal=(char)(temp+‘0‘)+hexadecimal;
else
hexadecimal=(char)(temp-10+‘A‘)+hexadecimal;
integer=integer/16;
}
System.out.println("The hexadecimal is "+hexadecimal);
}
}
//exercise 4.39
package fourthchapterexercise4;
public class ninth {
public static void main(String[] args) {
// TODO Auto-generated method stub
double sum=0;
for(int i=0;i<=5000;i++){
sum=5000+i*0.08;
if(sum>=30000){
System.out.println("minimum sales is "+(i-1));
System.exit(0);
}
}
for(int i=5000;i<=10000;i++ ){
sum=5000+5000*0.08+i*0.10;
if(sum>30000){
System.out.println("minimum sales is "+(i-1));
System.exit(0);
}
}
int i=10000;
while (sum<30000){
sum=5000+5000*0.08+10000*0.10+i*0.12;
i++;
}
System.out.println("minimum sales is "+(i-1));
System.exit(0);
}
}
//exercise 4.40
package fourthchapterexercise4;
public class tenth {
public static void main(String[] args) {
// TODO Auto-generated method stub
int positive=0;
int negative=0;
for(int i=1;i<=1000000;i++){
int temp=(int)(Math.random()*2);
if(temp==0)
positive++;
else
negative++;
}
System.out.println("The positive is "+positive);
System.out.println("The negative is "+negative);
}
}
//exercise 4.41
package fourthchapterexercise5;
import java.util.Scanner;
public class first {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in=new Scanner(System.in);
System.out.print("Enter numbers: ");
int integer=in.nextInt();
int max=0;
int count=0;
while (integer!=0){
if(max<integer){
max=integer;
count=0;
}
if(max==integer){
count++;
}
integer=in.nextInt();
}
System.out.println("The large number is "+max);
System.out.println("The occurrence count of the largest number is "+count);
}
}
//exercise 4.43
package fourthchapterexercise5;
import java.util.Scanner;
public class second {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in=new Scanner(System.in);
System.out.print("Enter the number of second :");
int seconds=in.nextInt();
while(true){
try {
//pause for a second
Thread.sleep(1000);
if((seconds-1)==0){
System.out.println("Stopped");
break;
}
if((seconds-1)==1){
System.out.println((seconds-1)+" second remaining");
seconds--;
continue;
}
System.out.println((seconds-1)+" seconds remaining");
seconds--;
//format
} catch (InterruptedException e) {
//If abnormal, the output to the console
e.printStackTrace();
}
}
}
}
//exercise 4.44
package fourthchapterexercise5;
import java.util.Scanner;
public class third {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in=new Scanner(System.in);
int count=0;
for(int i=1;i<=1000000;i++){
double x=Math.random()*2-1;
double y=Math.random()*2-1;
double distance1=Math.pow((x*x+y*y), 0.5);
double distance2=Math.pow((x-1)*(x-1)+(y-1)*(y-1),0.5);
if(distance1>distance2&&x>0&&y>0)
count++;
if(x<0)
count++;
}
double chance=count/1000000.0;
System.out.println("The chance is "+(int)(chance*10000)/100.0+"%");
}
}
//exercise 4.45
package fourthchapterexercise5;
public class fourth {
public static void main(String[] args) {
// TODO Auto-generated method stub
int count=0;
for(int i=1;i<=7;i++){
for(int j=1;j<=7;j++){
if(i!=j){
System.out.println(i+" "+j);
count++;
}
}
}
System.out.println("The numbers of combination is "+count);
}
}
//exercise 4.46
package fourthchapterexercise5;
import java.util.Scanner;
public class fifth {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in=new Scanner(System.in);
System.out.print("Enter an integer:");
int integer =in.nextInt();
//Judgment is a positive or negative number
boolean judge=false;
if(integer<0){
integer=-integer;
judge=true;
}
//Convert decimal number to a binary number
int count=0;
String decimal="";
while(integer!=0){
int temp=integer%2;
decimal=(char)(temp+‘0‘)+decimal;
integer=integer/2;
count++;
}
for(int i=1;i<=16-count;i++){
decimal=‘0‘+decimal;
}
//Judgment is a positive or negative number
if(judge){
char []decimalarr=decimal.toCharArray();
for(int i=0;i<decimalarr.length;i++){
if(decimalarr[i]==‘0‘)
decimalarr[i]=‘1‘;
else
decimalarr[i]=‘0‘;
}
for(int i=decimalarr.length-1;i>=0;i--){
if(decimalarr[i]==‘1‘){
decimalarr[i]=‘0‘;
}
else{
decimalarr[i]=‘1‘;
break;
}
}
System.out.print("The bits are ");
for(int i=0;i<decimalarr.length;i++){
System.out.print(decimalarr[i]);
}
}
else
System.out.println("The bits are "+decimal);
}
}
时间： 2024-11-03 21:52:12