[백준] 2847번 : 게임을 만든 동준이 - C

https://www.acmicpc.net/problem/2847

#include<stdio.h>

int main() {
    int n;
    scanf("%d",&n);
    int arr[n];
    int count=0;
    for(int i=0;i<n;i++) scanf("%d",&arr[i]);
    for(int i=n-1;i>0;i--){
        if(arr[i]<=arr[i-1]){
            count+=arr[i-1]-arr[i]+1;
            arr[i-1]=arr[i]-1;
        }
    }
    printf("%d",count);
}