【每日一题Day92】LC2299强密码检验器 II | 模拟状态压缩-优快云博客

本文链接：https://blog.youkuaiyun.com/Tikitian/article/details/128734119

该问题涉及设计一个算法来检查输入的字符串是否符合强密码的标准。这些标准包括最小长度为8，至少含有一种小写字母、大写字母、数字和特殊字符，且相邻字符不能相同。解决方案中，通过遍历字符串并使用位操作记录各种字符类型的存在，最后检查所有条件是否满足。

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强密码检验器 II【LC2299】

A password is said to be strong if it satisfies all the following criteria:

It has at least 8 characters.
It contains at least one lowercase letter.
It contains at least one uppercase letter.
It contains at least one digit.
It contains at least one special character. The special characters are the characters in the following string: "!@#$%^&*()-+".
It does not contain 2 of the same character in adjacent positions (i.e., "aab" violates this condition, but "aba" does not).

Given a string password, return true if it is a strong password. Otherwise, return false.

思路：首先判断密码长度是否大于等于8，若是则判断该密码是否包含至少一个数字、小写字母、大写字母以及特殊字符，并相邻字符不相同，若满足条件则返回true。

实现：使用一个变量记录该密码是否包含数字、小写字母、大写字母以及特殊字符，若都包含则返回true。

class Solution {
    public boolean strongPasswordCheckerII(String password) {
        int n = password.length();
        if (n < 8){
            return false;
        }
        int flag = 0;
        for (int i = 0; i < password.length(); i++){
            char c = password.charAt(i);
            if (i > 0 && password.charAt(i - 1) == c){
                return false;
            }
            if ( c >= '0' && c <= '9'){
                flag |= 1 << 0;
            }else if ( c >= 'a' && c <= 'z'){
                flag |= 1 << 1;
            }else if ( c >= 'A' && c <= 'Z'){
                flag |= 1 << 2;
            }else{
                flag |= 1 << 3;
            }
        }
        return flag >= 15;
    }
    
}