Increasing_arrays.txt

//...AKASH KESHRI...//
#include<bits/stdc++.h>
using namespace std;
#define gc getchar_unlocked
#define fo(i,n) for(i=0;i<n;i++)
#define Fo(i,k,n) for(i=k;k<n?i<n:i>n;k<n?i+=1:i-=1)
#define ll long long
#define deb(x) cout << #x << "=" << x << endl
#define deb2(x, y) cout << #x << "=" << x << "," << #y << "=" << y << endl
#define all(x) x.begin(), x.end()
#define clr(x) memset(x, 0, sizeof(x))
#define sortall(x) sort(all(x))
#define PI 3.1415926535897932384626
#define MOD 1000000007
typedef pair<int, int>	pii;
typedef vector<int>		vi;
typedef vector<pii>		vpii;
typedef vector<vi>		vvi;
//=======================
void solve() {
   ll n;
   cin>>n;
   ll sum=0;
   vector<ll> a(n);
   for(ll i=0;i<n;i++){
       cin>>a[i];
   }for(ll i=0;i<n-1;i++){
       if(a[i]>a[i+1]){
           sum+=abs(a[i]-a[i+1]);
           a[i+1]=a[i];
       }
   }cout<<sum<<endl;
}
int main() {
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
   // int t;
   // cin>>t;
   // while(t--){
      solve();
   // }
    return 0;
}