hdu 2024 C语言合法标识符

标识符：字母，数字和下划线组成，以字母或下划线开头

#include<iostream>#include<string>using namespace std;char a[55];int main(){int n;scanf("%d", &n);getchar();while(n--){gets(a);bool p = true;if(!(a[0] >= 'a' && a[0] <= 'z') && !(a[0] >= 'A' && a[0] <= 'Z') && a[0] != '_')p = false;for(int i = 0; a[i] != '\0'; i++){if(!(a[i] >= 'a' && a[i] <= 'z') && !(a[i] >= 'A' && a[i] <= 'Z') && a[i] != '_' && !(a[i] >= '0' && a[i] <= '9') ){p = false; break;}}if(p)puts("yes");elseputs("no");}return 0;}