Submission

Score: 100

User: Some1258

Problemset: ปริมาตรน้ำท่วม

Language: cpp

Time: 0.002 second

Submitted On: 2026-07-22 22:09:31

#include<bits/stdc++.h>
using namespace std;
int main(){
    int x;
    cin>>x;
    int arr[x];
    for(int i=0;i<x;i++){
        cin>>arr[i];
    }
    int start=arr[0];
    int sum=0;
    int ans=0;
    for(int i=1;i<x;i++){
        if(arr[i]>=start){
            ans+=sum;
            start=arr[i];
            sum=0;
            //cout<<sum<<endl;
        }
        sum+=start-arr[i];
    }
    sum=0;
    start=arr[x-1];
    for(int i=x-2;i>=0;i--){
        //cout<<start-arr[i]<<endl;
        if(arr[i]>start){
            ans+=sum;
            start=arr[i];
            //cout<<sum<<endl;
            sum=0;
        }
        sum+=start-arr[i];
    }
    cout<<ans;
}