C语言实验——合法的C标识符 (sdut oj)

C语言实验——合法的C标识符

Problem Description

Input

Output

Example Input

123You

Example Output

NO

Hint

Author

参考代码

#include<stdio.h>
#include<string.h>
int main()
{
char a[101];
int i,flag;
gets(a);
flag = 0;
if((a[0] >= 'a' && a[0] <= 'z') || (a[0] >= 'A' && a[0] <= 'Z') || (a[0] == '_'))
{
for(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'))
{
flag = 1;
}
else
{
flag = 0;
break;
}
}
}
if(flag == 1)
printf("YES\n");
else
printf("NO\n");
return 0;
}