HDU 2024 C语言合法标识符

#include <bits/stdc++.h>

using namespace std;

char s[111];
int len;

int A()
{
    if(s[0]>=‘a‘&&s[0]<=‘z‘||s[0]>=‘A‘&&s[0]<=‘Z‘||s[0]==‘_‘)
        return 1;
    else
        return 0;
}
int B()
{
    for(int i=1; i<len; i++)
    {
        if(s[i]>=‘a‘&&s[i]<=‘z‘||s[i]>=‘A‘&&s[i]<=‘Z‘||s[i]==‘_‘||
           s[i]>=‘0‘&&s[i]<=‘9‘)
            continue;
        else
            return 0;
    }
    return 1;
}

int main()
{
    int n;
    cin>>n;
    getchar();
    int sum=1;
    for(int i=1; i<=n; i++)
    {
        gets(s);
        //printf("!!!%s\n", s);
        len = strlen(s);
        sum=A()*B();
        //cout<<A()<<" "<<B()<<endl;
        if(sum==1&&len<=50)
            cout<<"yes"<<endl;
        else
            cout<<"no"<<endl;
    }
    return 0;
}