Question

杭电acmhttp://acm.hdu.edu.cn/showproblem.php?pid=2024不知道哪里错了

#include<iostream>
#include<string>
#include<ctype.h>
#include<fstream>
using namespace std;

int main()
{
ifstream cin("a.txt");
int n,len;
int i;
string s;
while(cin>>n)
{
cin.ignore();
while(n--)
{
int flag=0;
getline(cin,s);
if(!isalpha(s[0]) || s[0]!='_')
{
cout<<"no"<<endl;
continue;
}
len=s.length();
for(i=1;i<len;i++)
{
if(!isalnum(s[i]) || s[i]!='_')
{
flag=0;
cout<<"no"<<endl;
break;
}
}
if(flag) cout<<"yes"<<endl;
}
}
return 0;
}

Answer 1

杭电顶起 ，，，，，，，，，，