🐣 문제

링크 : https://school.programmers.co.kr/learn/courses/30/lessons/42862

🐥 코드

#include <string>
#include <vector>
#include <algorithm>
using namespace std;
int arr[31] = {0, };

int solution(int n, vector<int> lost, vector<int> reserve) {
    int answer = 0;
    for(int i: lost)
        arr[i]--;
    for(int i: reserve)
        arr[i]++;
    
    for(int i = 1; i <= n; i++){
        if(arr[i] == -1){
            if(arr[i-1] == 1){
                arr[i-1] = arr[i] = 0; 
            }
            else if(arr[i+1] == 1){
                arr[i+1] = arr[i] = 0;
            }
        }
        if(arr[i] >= 0) answer++;
    }
    return answer;
}