#include <iostream> using namespace std; double Sum2(double x, double y) { double sum = 0; if (x + y < 0.0000000001) { cout << "x, y 的调和数为无穷大;\n"; system("pause"); exit(0); } sum = 2.0*x*y / (x + y); return sum; } void test7_1() { double x; double y; double sum = 0; while ((cin>>x>>y) && x != 0 && y!=0) { sum = Sum2(x, y); cout << "x,y的调和为: " << sum << endl; } } /************************************************************************/ /* 2 */ /************************************************************************/ const int SIZE = 10; int GetScores(double scores [],int *size) { cout << "Enter the scores( press q to quit).\n"; int i = 0; for (i = 0; i < 10 && cin >> scores[i]; i++) { if (scores[i]<0) { cout << "score below zero, bad input.\n"; cout << "Input terminated.\n"; return -1; } } *size = i; return 0; } void Show(const double * scores, int size) { int i = 0; for (i = 0; i < size; i++) { cout << scores[i] << " "; } cout << endl; } double Average(const double *scores, int size) { double sum = 0; if (size == 0) { return 0; } for (int i = 0; i < size; i ++) { sum += scores[i]; } return sum/size; } void test7_2() { int size = 0; double scores[SIZE] = { 0 }; int ret = 0; ret = GetScores(scores, &size); while (ret != 0) { cout << "Please input again.\n"; ret = GetScores(scores, &size); } Show(scores, size); double avg = Average(scores, size); cout << "平均成绩为:" << avg << endl; } /************************************************************************/ /* 3 */ /************************************************************************/ typedef struct Box { char maker[40]; float height; float width; float length; float volume; }box; void ShowBox(box b1) { cout << "Showing the box......\n"; cout << b1.maker << endl; cout << b1.height << endl; cout << b1.width << endl; cout << b1.length << endl; cout << b1.volume << endl; } void GetVol(box * b1) { b1->volume = b1->height *b1->length*b1->width; } void test7_3() { box b1 = { "Cat", 10, 2, 3, 0 }; ShowBox(b1); GetVol(&b1); ShowBox(b1); } /************************************************************************/ /* 4 */ /************************************************************************/ void test7_4() { } /************************************************************************/ /* 5 */ /************************************************************************/ long GetFactorial(int n) { if (n == 0 || n == 1) { return 1; } else return n*GetFactorial(n - 1); } void test7_5() { int n = 0; cin >> n; if (n < 0) { cout << "bad input.\nprogram terminated.\n"; return; } cout << n << "! = " << GetFactorial(n)<<endl; } void test7_6() { } /************************************************************************/ /* 7 */ /************************************************************************/ const int Max = 5; double * full_array(double ar[], int limit) { double *ar_end = ar; double tmp = 0; for (int i = 0; i < limit; i++, ar_end++) { cout << "Enter value #" << (i + 1) << ": "; cin >> tmp; if (!cin) { cin.clear(); while (cin.get()!=‘\n‘) { continue; } cout << "Bad input;input process terminated.\n"; break; } else if (tmp < 0) { break; } *ar_end = tmp; } return --ar_end; } void show_array(double ar[], const double *ar_end) { double *pt = ar; for (int i = 0; pt <= ar_end; pt++, i++) { cout << "Property #" << (i + 1) << ": $"; cout << *pt << endl; } } void revalue(double r, double *ar, double *ar_end) { double *pt = ar; for (; pt <= ar_end ; pt++) { *pt *= r; } } void test7_7() { double properties[Max]; double *ar_end = NULL; ar_end = full_array(properties, Max); show_array(properties,ar_end); if (ar_end - properties > 0) { cout << "Enter revaluation factor: "; double factor; while (!(cin >> factor)) { cin.clear(); while (cin.get()!= ‘\n‘) { continue; } cout << "Bad input. input process terminated."; } revalue(factor, properties, ar_end); show_array(properties, ar_end); } cout << "Done.\n"; cin.get(); cin.get(); } /************************************************************************/ /* 8 */ /************************************************************************/ const int Seasons = 4; const char * Snames[Seasons] = { "Spring", "Summer", "Fall", "Winter" }; void fill(double expenses[], int Seasons) { for (int i = 0; i < Seasons; i++) { cout << "Enter " << Snames[i] << " expense: "; cin >> expenses[i]; } } void show(double expense[], int Seasons) { double total = 0; cout << "EXPENSE\n"; for (int i = 0; i < Seasons; i++) { cout << Snames[i] << ": $" << expense[i] << endl; total += expense[i]; } cout << "Total Expense: $" << total << endl; } void test7_8() { double expense[Seasons] = { 0 }; fill(expense, Seasons); show(expense, Seasons); } /************************************************************************/ /* 9 */ /************************************************************************/ const int Size = 30; typedef struct Student{ char fullname[Size]; char hobby[Size]; int ooplevel; }student; int getInfo(student pa[], int n) { int i = 0; for (i = 0; i < n; i++) { cout << "Student #" << i + 1 << ":\n"; cout << "Enter name: "; cin >> pa[i].fullname; if (!cin) { cin.clear(); while (cin.get()!= ‘\n‘) { continue; } cout << "bad input. input process terminated.\n"; } cout << "Enter hobby:"; cin >> pa[i].hobby; cout << "Enter ooplevel:"; cin >> pa[i].ooplevel; } return i; } void display1(student st) { cout << "Student info:\n"; cout << "name: " << st.fullname << endl; cout << "hobby: " << st.hobby << endl; cout << "ooplevel" << st.ooplevel << endl; } void display2(student *ps) { cout << "Student info:\n"; cout << "name: " << ps->fullname << endl; cout << "hobby: " << ps->hobby << endl; cout << "ooplevel" << ps->ooplevel << endl; } void display3(const student pa[], int n) { int i = 0; for (; i < n; i++) { cout << "Student #" << i + 1<< "info:"<< endl; cout << "name: " << pa[i].fullname << endl; cout << "hobby: " << pa[i].hobby << endl; cout << "ooplevel" << (pa+i)->ooplevel << endl; } } void test7_9() { cout << "Enter class size: "; int class_size; cin >> class_size; while (cin.get()!= ‘\n‘) { continue; } student *ptr_stu = new student[class_size]; int entered = getInfo(ptr_stu, class_size); for (int i = 0; i < entered; i++) { display1(ptr_stu[i]); display2(ptr_stu + i); } display3(ptr_stu, entered); delete [] ptr_stu; cout << "Done.\n"; } double add(double x, double y) { return x + y; } double sub(double x, double y) { return x - y; } double mul(double x, double y) { return x*y; } void test7_10() { double(*calculate[3])(double, double); calculate[0] = add; calculate[1] = sub; calculate[2] = mul; for (int i = 0; i < 3; i++) { cout << calculate[i] << ": "<<calculate[i](5, 2) << endl; } } int main() { test7_10(); system("pause"); return 0; }
时间: 2024-10-09 06:43:51