华为OJ：判断两个IP是否属于同一子网

以你之姓@ 2022-08-09 00:47 188阅读 0赞

**这道题目要判断输入的子网掩码和ip地址是否合法。**

#include <stdarg.h>
    #include <stdio.h>
    #include <iostream>
    #include <vector>
    #include <string.h>
    #include <algorithm>
    #include <stdlib.h>
    #include <memory>
    #include <string.h>
    #include <set>
    #include <map>
    #include <sstream>
    #include <string>
    
    using namespace std;
    
    int checkNetSegment(string mask, string ip1, string ip2) 
    {     
    	if(mask.size() == 0||ip1.size() == 0||ip2.size() == 0)
    	{
    		return 1;
    	}
        /*在这里实现功能*/
    	int i = 0, j = 0;
    	char szStrMask[100] = {0};
    	char szStrip1[100] = {0};
    	char szStrip2[100] = {0};
    
    	int aMask[4] = {0};
    	int aip1[4] = {0};
    	int aip2[4] = {0};
    
    	char* taken = NULL;
    
    	/* ip1与子网掩码求& */
    	memset(szStrMask,0,100);
    	memset(szStrip1,0,100);
    	memset(szStrip2,0,100);
    
    	strcpy(szStrMask,mask.c_str());
    	strcpy(szStrip1,ip1.c_str());
    	strcpy(szStrip2,ip2.c_str());
    
    	/* 把子网掩码的四个int型数据取出来 */
    	taken = strtok(szStrMask,".");
    	i = 0;
    	while(taken != NULL)
    	{
    		aMask[i] = atoi(taken);
    
    		if(i == 0)
    		{
    			if(aMask[i] != 255)
    			{
    				return 1;
    			}
    		}
    		else
    		{
    			if(aMask[i] > 255 || aMask[i] < 0)
    			{
    				return 1;
    			}
    		}
    		i++;
    		taken = strtok(NULL,".");
    	}
    
    	/* 判断是否合法 */
    	if(i != 4)
    	{
    		return 1;
    	}
    
    	/* 把ip1的四个int型数据取出来 */
    	taken = strtok(szStrip1,".");
    	i = 0;
    	while(taken != NULL)
    	{
    		aip1[i] = atoi(taken);
    
    		if(aip1[i] > 255 || aip1[i] < 0)
    		{
    			return 1;
    		}
    		i++;
    		taken = strtok(NULL,".");
    	}
    
    	/* 判断是否合法 */
    	if(i != 4)
    	{
    		return 1;
    	}
    
    	/* 把ip2的四个int型数据取出来 */
    	taken = strtok(szStrip2,".");
    	i = 0;
    	while(taken != NULL)
    	{
    
    		aip2[i] = atoi(taken);
    		if(aip2[i] > 255 || aip2[i] < 0)
    		{
    			return 1;
    		}
    
    		i++;
    		taken = strtok(NULL,".");
    	}
    
    	/* 判断是否合法 */
    	if(i != 4)
    	{
    		return 1;
    	}
    
    	/* 将mask与ip1运算 */
    	for(i = 0; i < 4; i++)
    	{
    		aip1[i] = (aMask[i] & aip1[i]);
    	}
    
    	/* 将mask与ip2运算 */
    	for(i = 0; i < 4; i++)
    	{
    		aip2[i] = (aMask[i] & aip2[i]);
    	}
    
    	/* 判断是否在同一个网段 */
    	for(i = 0; i < 4; i++)
    	{
    		if(aip1[i] != aip2[i])
    		{
    			return 2;
    		}
    	}
    	
        return 0;
    }
    
    int main()
    {
    
    	string mask, ip1, ip2;
    	
    	cin >> mask >> ip1 >> ip2;
    
    	cout << checkNetSegment(mask,ip1,ip2) << endl;;
    
    	return 0;
    }