Submission

Score: 100

User: rice_ot

Problemset: ปริมาตรน้ำท่วม

Language: cpp

Time: 0.002 second

Submitted On: 2025-10-24 20:55:26

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

int main(){
  int n; cin>>n;
  vector<int> num(n);
  for(auto& i : num) cin>>i;
  
  int lmax = num[0], rmax = num[n-1];
  int start = 1, end = n-2;
  
  int res = 0;
  while(start <= end){
    if(lmax <= rmax){
      if(lmax - num[start] >= 0) res+=lmax-num[start];
      else lmax = num[start];
      start++;
    }
    else if(lmax > rmax){
      if(rmax - num[end] >= 0) res+=rmax-num[end];
      else rmax = num[end];
      end--;
    }
  }
  cout<<res;
}