HDU2024 标识符

#include<stdio.h>#include<string.h>int main(){    char s[55];    int n,m,i;    while(scanf("%d",&n)!=EOF){        getchar();        while(n--){        gets(s);        m=strlen(s);        if(s[0]<='9'&&s[0]>=0){            printf("no\n");            continue;        }        bool flage=1;        for (i=0;i<m;i++)        {            if(s[i]>='a'&&s[i]<='z'||s[i]<='Z'&&s[i]>='A'||s[i]=='_'||s[i]>='0'&&s[i]<='9');            else flage=0;        }        if(flage) printf("yes\n");        else printf("no\n");    } }  return 0;}