4. 위장

https://programmers.co.kr/learn/courses/30/lessons/42578

코딩테스트 연습 - 위장

딕셔너리 (맵) 자료형을 이용해서 카운트할 수 있습니다.  

파이썬

def solution(clothes):
    temp = {}
    for _, cat in clothes:
        if cat in temp:
            temp[cat] += 1
        else:
            temp[cat] = 1
    answer = 1
    for each in temp.values():
        answer *= each + 1
    return answer - 1

딕셔너리의 setdefault를 사용하면 코드를 더 줄일 수 있습니다. 

def solution(clothes):
    temp = {}
    for _, cat in clothes:
        temp.setdefault(cat, 0)
        temp[cat] += 1
    answer = 1
    for each in temp.values():
        answer *= each + 1
    return answer - 1

딕셔너리의 get을 이용하면 한 줄 더 줄일 수 있습니다. 

def solution(clothes):
    temp = {}
    for _, cat in clothes:
        temp[cat] = temp.get(cat, 0) + 1
    answer = 1
    for each in temp.values():
        answer *= each + 1
    return answer - 1

함수형으로.. 

from collections import Counter
from functools import reduce


def solution(clothes):
    return reduce(lambda x, y: x * (y + 1), Counter(cat for _, cat in clothes).values(), 1) - 1

 

자바스크립트

function solution(clothes) {
    let temp = {};
    for (let i = 0; i < clothes.length; i++){
        if (clothes[i][1] in temp) temp[clothes[i][1]]++
        else temp[clothes[i][1]] = 1
    }
    var answer = 1;
    for (let each in temp) answer *= (temp[each] + 1)
    return answer - 1;
}

 

자바

import java.util.HashMap;

class Solution {
    public int solution(String[][] clothes) {
        HashMap<String, Integer> clothesMap = new HashMap<>();
        for (String[] each : clothes) {
            if (!clothesMap.containsKey(each[1])) {
                clothesMap.put(each[1], 1);
            }
            clothesMap.put(each[1], clothesMap.get(each[1]) + 1);
        }
        var total = 1;
        for (var key : clothesMap.keySet()) {
            total *= clothesMap.get(key);
        }
        return total - 1;
    }
}

 

코틀린

import java.util.HashMap

class Solution {
    fun solution(clothes: Array<Array<String>>): Int {
        val clothesMap = HashMap<String, Int>()
        for (each in clothes) {
            if (!clothesMap.containsKey(each[1])) {
                clothesMap[each[1]] = 1
            }
            clothesMap[each[1]] = clothesMap[each[1]]!! + 1
        }
        var total = 1
        for (key in clothesMap.keys) {
            total *= clothesMap[key]!!
        }
        return total - 1
    }
}

 

고

func solution(clothes [][]string) int {
    temp := make(map[string]int)
    for _, cloth := range clothes{
        temp[cloth[1]]++
    }
    answer := 1
    for _, v := range temp{
        answer *= v + 1
    }
    return answer - 1
}

 

C#

using System.Collections.Generic;

public class Solution
{
    public int solution(string[,] clothes)
    {
        Dictionary<string, int> counts = new Dictionary<string, int>();
        for (int i = 0; i < clothes.GetLength(0); i++)
        {
            if (!counts.ContainsKey(clothes[i, 1]))
                counts[clothes[i, 1]] = 0;
            counts[clothes[i, 1]]++;
        }
        int answer = 1;
        foreach (var n in counts)
        {
            answer *= n.Value + 1;
        }
        return answer - 1;
    }
}