HDU 2024 C语言合法标识符

#include<stdio.h>
#include<string.h>
#include<iostream>
using namespace std;
char z[57];
int main()
{
    int m;
    while(scanf("%d",&m)!=EOF)
    {
        getchar();
        while(m--)
        {

            memset(z,0,sizeof(z));
            int a ;
            gets(z);
            if((z[0]>='a'&&z[0]<='z')||(z[0]>='A'&&z[0]<='Z')||z[0]=='_')
            {
                for( a=1; a<strlen(z); a++)
                {
                    if((z[a]>='A'&&z[a]<='Z')||(z[a]>='a'&&z[a]<='z')||(z[a]>='0'&&z[a]<='9')||z[a]=='_')
                        continue;
                    else break;
                }
                if(a==strlen(z))printf("yes\n");
                else printf("no\n");//printf("kdf");
            }
            else printf("no\n");

        }
    }
    return 0;
}