可把初学者的我憋惨了，能告诉我个正确的做法或者我哪儿错了不😂

Question

Answer 1

修改为if ... , else if ...,else if ..., else 结构,才可以把多个条件判断逻辑连接起来

#include <stdio.h>
#include <string.h>
int main()
{
    char m[81];
    char ch;
    int i=0;
    int  a, b, c, d, length;
    a=  b= c= d= length = 0;
    while ((ch=getchar()) != '#')
    {  
        if (ch >= '0' && ch <= '9')
        {
            a++;
        }
        else if (ch >= 'A' && ch <= 'Z')
        {
            b++;
        }
        else if (ch >= 'a' && ch <= 'z')
        {
            c++;
        }
        else
        {
            d++;
        }
        m[i++]=ch;
    }    
    m[i]='\0';
    length = i;   
    if (length < 10 || length > 16)
    {
        printf("NO");
        return 0;
    }    
    if (a > 0 && b > 0 && c > 0 && d > 0)
    {
        printf("YES");
    }
    else
        printf("NO");
    return 0;
}