【密码】 （C语言代码）（简单的常规思路）

#include<stdio.h>
int main()
{
    int m,i;
    scanf("%d",&m);
    for(i=0;i<m;i++)
    {
        char c[50],otherchar[8]="~!@#$%^";
        scanf("%s",c);
        int length=0,j=0;
        while(c[j]!='\0')
        {
          length++;
            j++;
        }
        if(length<8||length>16) {printf("NO\n");continue;}
        else
        {
           int count[4]={0},k=0,flag=0;
            while(c[k]!='\0')
            {
                if(c[k]>='A'&&c[k]<='Z') count[0]++;
                if(c[k]>='a'&&c[k]<='z') count[1]++;
                if(c[k]>='0'&&c[k]<='9') count[2]++;
                int t=0;
                for(;t<7;t++)
                    if(c[k]==otherchar[t])
                    count[3]++;
                k++;
            }
            for(k=0;k<4;k++)
                if(count[k]!=0) flag++;
            if(flag>=3) printf("YES\n");
            else printf("NO\n");
         }
    }
    return 0;
}