题解 | 判断字母

#include <stdio.h>
int main()
{
	char ch1 = '0'; 
	scanf("%c", &ch1);
	if (ch1 >= 65 && ch1 <= ch1 <= 90 || ch1 >= 97 && ch1 <= 122)
	{
		printf("YES\n"); 
	}
	else
	{
		printf("NO\n"); 

	}

	return 0;
}