codex-iter04.cpp

#include <iostream>
#include <vector>
#include <algorithm>
#include <omp.h>
 
using namespace std;
 
int main()
{
  int n;
  // cout << "Print the minimum number of moves.";
  cin >> n;
 
  vector<int> arr(n);
 
  for (int i = 0; i < n; i++)
  {
    cin >> arr[i];
  }
 
  long long moves = 0;
 
#pragma omp parallel for reduction(+ : moves)
  for (int i = 1; i < n; i++)
  {
    if (arr[i] < arr[i - 1])
    {
      moves += arr[i - 1] - arr[i];
      arr[i] = arr[i - 1];
    }
  }
 
  cout << moves << endl;
 
  return 0;
}