Increasing Array

input/code.cpp: In function 'int main()':
input/code.cpp:7:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &N);
     ~~~~~^~~~~~~~~~
input/code.cpp:10:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", arr+i);
         ~~~~~^~~~~~~~~~~~~

#include <stdio.h>

int N;
int arr[200010];

int main() {
    scanf("%d", &N);
    for (int i = 0; i < N; i++)
    {
        scanf("%d", arr+i);
    }
    int preMax = -1;
    long long res = 0;
    for (int i = 0; i < N; i++)
    {
        if (preMax < arr[i])
        {
            preMax = arr[i];
        }
        res += preMax - arr[i];
    }
    printf("%lld\n", res);
    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