牛客网真题2019-33-字符串长度最大乘积

双循环搜索+排序优化+Set集合优化
处理输入，去除"[" "]" "" "三种字符，再split得到字符串数组

import java.util.*;

public class Main {
    public static boolean containSet(Set<Character> set, String str){
        for(int i = 0; i < str.length(); i++){
            if(set.contains(str.charAt(i))){
                return true;
            }
        }
        return false;
    }

    public static void main(String[] args){
        Scanner scanner = new Scanner(System.in);
        String[] s = scanner.nextLine().replace("[", "")
                .replace("]", "")
                .replace("\"", "").split(",");
        System.out.println(Arrays.toString(s));
        Arrays.sort(s, (o1, o2) -> Integer.compare(o2.length(), o1.length()));
        int sum = 0;
        for(int i = 0; i < s.length; i++){
            Set<Character> set = new HashSet<>();
            s[i].chars().forEach((c) -> set.add((char) c));
            for(int j = i; j < s.length; j++){
                if(!containSet(set, s[j])){
                    sum = Math.max(s[i].length() * s[j].length(), sum);
                }
            }
        }
        System.out.println(sum);
    }
}