Submission

Score: 100

User: NovemNotes

Problemset: ปริมาตรน้ำท่วม

Language: cpp

Time: 0.002 second

Submitted On: 2026-05-09 10:02:16

#include <bits/stdc++.h>
using namespace std;

int32_t main(){
	ios_base::sync_with_stdio(false);cin.tie(NULL);
	int n;cin >> n;
	int v[n+9];
	int l[n+9],r[n+9];
	int ans = 0;
	for(int i=1;i<=n;i++)cin >> v[i];
	int val = v[1],idx = 1;
	for(int i=1;i<=n;i++){
		if(v[i] > val){
			val = v[i];
			idx = i;
		}
		l[i] = idx;
	}
	val = v[n] , idx = n;
	for(int i=n;i>=1;i--){
		if(v[i] > val){
			val = v[i];
			idx = i;
		}
		r[i] = idx;
	}
	for(int i=1;i<=n;i++){
		int h = min(v[l[i]],v[r[i]]);
		ans += (h - v[i]);
	}
	cout << ans << "\n";
	return 0;
}