| 描述 |
请解析IP地址和对应的掩码，进行分类识别。要求按照A/B/C/D/E类地址归类，不合法的地址和掩码单独归类。 所有的IP地址划分为 A,B,C,D,E五类 A类地址1.0.0.0~126.255.255.255; B类地址128.0.0.0~191.255.255.255; C类地址192.0.0.0~223.255.255.255; D类地址224.0.0.0~239.255.255.255； E类地址240.0.0.0~255.255.255.255 私网IP范围是： 10.0.0.0～10.255.255.255 172.16.0.0～172.31.255.255 192.168.0.0～192.168.255.255 子网掩码为前面是连续的1，然后全是0 |
|---|---|
| 知识点 | 字符串,循环,查找,搜索,排序,函数,指针,枚举,位运算,结构体,联合体,文件操作,递归 |
| 运行时间限制 | 0M |
| 内存限制 | 0 |
| 输入 |
多行字符串。每行一个IP地址和掩码，已~隔开。如： 10.70.44.68~255.254.255.0 1.0.0.1~255.0.0.0 192.168.0.2~255.255.255.0 19..0.~255.255.255.0 |
| 输出 |
统计A、B、C、D、E、错误IP地址或错误掩码、私有IP的个数，之间以空格隔开，根据上面的IP，可以得到： 1.0.0.1~255.0.0.0 ----A类 192.168.0.2~255.255.255.0 ----C类，私有 10.70.44.68~255.254.255.0----错误的掩码 19..0.~255.255.255.0-----错误的IP 可以得到统计数据如下： 1 0 1 0 0 2 1 |
| 样例输入 | 10.70.44.68~255.254.255.0 1.0.0.1~255.0.0.0 192.168.0.2~255.255.255.0 19..0.~255.255.255.0 |
| 样例输出 | 1 0 1 0 0 2 1 |
package com.oj;
import java.util.Scanner;
public class TestOj {
private static boolean judge(int[] mask){
StringBuilder masks = new StringBuilder();
for(int i = 0;i < mask.length; i++)
masks.append(Integer.toBinaryString(mask[i]));
//System.out.println(masks.toString());
String str = new String(masks.toString());
for(int i = 0;i < str.length()-1; i++)
if(str.charAt(i)==‘0‘&&str.charAt(i+1)==‘1‘)
return false;
return true;
}
public static void main(String[] args) {
int countA = 0,countB = 0,countC = 0,countD = 0,countE = 0,countError = 0,countPrivate = 0;
Scanner in = new Scanner(System.in);
while(in.hasNext()){
String str = in.nextLine();
String[] data = str.split("~");
String ip = data[0];
String mask = data[1];
String[] ips = ip.split("\\.");
String[] masks = mask.split("\\.");
if(ips.length!=4&&masks.length!=4){
countError++;
//System.out.println("Error");
continue;
}
boolean flag = false;
int[] iips = new int[4];
for(int i = 0;i < 4; i++){
try{
iips[i] = Integer.parseInt(ips[i]);
if(iips[i]<0&&iips[i]>255)
flag = true;
}catch(NumberFormatException e){
flag = true;
break;
}
}
if(flag){
countError++;
//System.out.println("Error");
continue;
}
flag = false;
int [] imasks = new int[4];
for(int i = 0;i < 4; i++){
try{
imasks[i] = Integer.parseInt(masks[i]);
if(imasks[i]<0&&imasks[i]>255)
flag = true;
}catch(NumberFormatException e){
flag = true;
break;
}
}
if(flag){
countError++;
//System.out.println("Error");
continue;
}
if(!judge(imasks)){
countError++;
//System.out.println("Error");
continue;
}
if(iips[0]<=126&&iips[0]>=1){
countA++;
//System.out.println("A");
if(iips[0]==10)
countPrivate++;
continue;
}else if(iips[0]>=128&&iips[0]<=191){
countB++;
if(iips[1]>=16&&iips[1]<=31)
countPrivate++;
//System.out.println("B");
continue;
}else if(iips[0]>=192&&iips[0]<=223){
countC++;
if(iips[1]==168)
countPrivate++;
//System.out.println("C");
continue;
}else if(iips[0]>=224&&iips[0]<=239){
countD++;
//System.out.println("D");
continue;
}else if(iips[0]>=240&&iips[0]<=255){
countE++;
//System.out.println("E");
continue;
}
}
System.out.println(countA+" "+countB+" "+countC+" "+countD+" "+countE+" "+countError+" "+countPrivate);
}
}
时间： 2024-08-01 23:24:52