Increasing Array

#include <iostream>
using namespace std;
int main()
{
    int n;
    cin >> n;
    int l;
    cin >> l;
    long long r = 0;
    for (int i = 1; i < n; i++)
    {
        int t;
        cin >> t;
        if (t < l)
        {
            r += l - t;
            t = l;
        }
        l = t;
    }
    cout << r;
    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED