[programmers] 가장 많이 받은 선물

08 May 2023 in Algorithm on Algorithm

https://school.programmers.co.kr/learn/courses/30/lessons/258712

import java.util.*;

class Solution {
    public int solution(String[] friends, String[] gifts) {
        int answer = 0;
        Map<String,Friend> friend = new HashMap<>();

        for(String name : friends){
            friend.put(name, new Friend());
        }

        for(String gift : gifts){
            String[] temp = gift.split(" ");
            friend.get(temp[0]).add(temp[1]);
            friend.get(temp[1]).minus();
        }

        for(String give : friends){
            int tempCnt = 0;
            for(String get : friends){
                if(!give.equals(get)){
                    Friend give_person = friend.get(give);
                    Friend get_person = friend.get(get);
                    int give_cnt = give_person.m.getOrDefault(get,0);
                    int get_cnt = get_person.m.getOrDefault(give,0);

                    if( give_cnt > get_cnt || (give_cnt == get_cnt && give_person.index > get_person.index) )
                        tempCnt++;
                }
            }
            answer = Math.max(tempCnt,answer);
        }

        return answer;
    }
}

class Friend{
    int index;
    Map<String,Integer> m;

    Friend(){
        this.m = new HashMap<>();
        index = 0;
    }

    void add(String name){
        m.put(name, m.getOrDefault(name,0) + 1 );
        index++;
    }

    void minus(){
        index--;
    }
}