[백준/그리디/C++] 2847번 게임을 만든 동준이

문제는 여기!

#include <bits/stdc++.h>

using namespace std;

int N;
int level[101];
int answer = 0;

void solve(){
    int tmp = level[N];
    for(int i=N-1; i>=1; i--){
        while(tmp <= level[i]){
            level[i]--;
            answer++;
        }
        tmp = level[i];
    }
}

void input(){
    cin >> N;
    for(int i=1; i<=N; i++){
        cin >> level[i];
    }
}

int main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    input();
    solve();
    cout << answer;

    return 0;
}