杭电 hdu 2024

C语言合法标识符：

#include<iostream>
#include<string.h>
#include<stdio.h>
using namespace std;
#define N 1000
char str[N];
int main(){
    int n;
    cin>>n;
    cin.ignore();
    while(n--){
        gets(str);
        int len=strlen(str);
        int t=0;
        if((str[0]<='z'&&str[0]>='a')||(str[0]<='Z'&&str[0]>='A')||
                str[0]=='_'){
            int i;
            for(i=1;i<len;++i){
                if((str[i]<='z'&&str[i]>='a')||(str[i]<='Z'&&str[i]>='A')||
                        (str[i]<='9'&&str[i]>='0')||str[i]=='_')
                    continue;
                else{
                    cout<<"no"<<endl;
                    t=1;
                    break;
                }
            }
        }
        else{
            t=1;
            cout<<"no"<<endl;
        }
        if(t==0)
            cout<<"yes"<<endl;
    }
    return 0;
}