IP判断 （C++代码）

#include<bits/stdc++.h>
using namespace std;
const int Max=300;
int main()
{
    char str[Max],tt[Max];
    int dian;
    while(cin>>str)
    {
        bool flag=true;
        for(int i=0,k=0;i<strlen(str);++i)
        {
            if((str[i]<'0'||str[i]>'9')&&str[i]!='.')
            {
                flag=false;
                break;
            }
            else if(str[i]!='.')
            {
                tt[k++]=str[i];
            }
            else if(str[i]='.'||i==strlen(str)-1)
            {
                tt[k]='\0';
                int ak,l;
                l= strlen(tt);
                if(tt[0]==0&&l>1)
                {
                   flag = false;
                    break;
                }
                ak=atoi(tt);
                if(ak<0||ak>255)
                {
                    flag = false;
                    break;
                }
                memset(tt,0,sizeof(tt));
                k=0;
            }
        }
         if(flag)
            cout<<"Y"<<endl;
         else
            cout<<"N"<<endl;
    }
   return 0;
}

解题思路:

注意事项:

参考代码: