题解 | #密码验证合格程序#

#include <stdio.h>

static int judgeType(char *str, int len)
{
    if(!str || len <= 0)
    {
        return -1;
    }
    int strType[4] = {0};
    for(int i = 0; i < len; i++)
    {
        if(str[i] >= 'a' && str[i] <= 'z')
        {
            strType[0] = 1;
        }
        else if(str[i] >= 'A' && str[i] <= 'Z')
        {
            strType[1] = 1;
        }
        else if(str[i] >= '0' && str[i] <= '9')
        {
            strType[2] = 1;
        }
        else
        {
            strType[3] = 1;
        }
    }
    if(strType[0] + strType[1] + strType[2] + strType[3] < 3)
    {
        return -1;
    }
    return 0;
}

static int checkRepetition(char *str)	//快慢指针循环判断子串是否重复
{
    if(!str)
    {
        return -1;
    }
    int fast = 1;    //快指针
    int slow = 0;    //慢指针
    int count = 0;   //相同子串计数
    while(str[slow] != '\0')
    {
        if(str[fast++] == str[slow])    //快指针开始和数组首位比较
        {
            for(int i = 0; i < 3; i++)
            {
                if(str[fast+i-1] == '\0')//说明到结尾了,str[fast+i-1]表示慢指针
                {
                    break;
                }
                else if(str[fast+i-1] == str[slow+i])
                {
                    count++;
                }
            }
            if(count >= 3)
            {
                return -1;    //说明子串重复大于3个
            }
            else
            {
                count = 0;
            }
        }
        else if(str[fast] == '\0')    //说明一轮比较结束
        {
            slow++;
            fast = slow+1;
        }
    }
    return 0;
}

int main()
{
    char str[100] = {0};
    while(scanf("%s", str) != EOF)
    {
        int len = strlen(str);
        if(len < 9)    //1.长度超过8位
        {
            printf("NG\n");
        }
        else
        {
            if(judgeType(str, len) < 0)    //2.包括大小写字母.数字.其它符号,以上四种至少三种
            {
                printf("NG\n");
            }
            else
            {
                if(checkRepetition(str) < 0)
                {
                    printf("NG\n");
                }
                else
                {
                    printf("OK\n");
                }
            }
        }
    }
    return 0;
}