题解 | 密码强度检查

import java.util.Scanner;
import java.util.HashSet;
import java.util.Set;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int T = sc.nextInt();
        sc.nextLine();
        String[] passwords = new String[T];
        String[] strengths = new String[T];
        REAL827 real827 = new REAL827();
        for (int i = 0; i < T; i++) {
            passwords[i] = sc.next();
            strengths[i] = real827.passwordStrength(passwords[i]);
        }
        for (int i = 0; i < T; i++) {
            System.out.println(strengths[i]);
        }
    }
}

class REAL827 {
    public String passwordStrength(String password) {
        int[] types = new int[password.length()];
        if (password.length() < 8) {
            return "Weak";
        } else {
            for (int i = 0; i < password.length(); i++) {
                if (password.charAt(i) >= 33 && password.charAt(i) <= 126) {
                    if (password.charAt(i) >= 97 && password.charAt(i) <= 122) {
                        types[i] = 1;
                    } else if (password.charAt(i) >= 65 && password.charAt(i) <= 90) {
                        types[i] = 2;
                    } else if (password.charAt(i) >= 48 && password.charAt(i) <= 57) {
                        types[i] = 3;
                    } else {
                        types[i] = 4;
                    }
                }
            }
        }
        Set<Integer> typesSet = new HashSet<>();
        for (int i = 0; i < password.length(); i++) {
            typesSet.add(types[i]);
        }
        if (typesSet.contains(1) && typesSet.contains(2) && typesSet.contains(3) &&
                typesSet.contains(4)) {
            return "Strong";
        } else if ((typesSet.contains(1) && typesSet.contains(2) &&
                    typesSet.contains(3)) ||
                   (typesSet.contains(2) && typesSet.contains(3) && typesSet.contains(4)) ||
                   (typesSet.contains(1) && typesSet.contains(3) && typesSet.contains(4)) ||
                   (typesSet.contains(1) && typesSet.contains(2) && typesSet.contains(4))) {
            return "Medium";
        } else {
            return "Weak";
        }
    }
}

可能比较笨，但确实以目前水平最大限度在缩短时间复杂度