Maximum sum

#define F first
#define S second
#define PB push_back
#define MP make_pair
#define REP(i, a, b) for (int i = a; i < b; ++i)
#define REPI(i, a, b) for (int i = a; i <= b; ++i)
#define BR "\n"

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef vector<bool> vb;
typedef pair<int, int> pi;

int main() {
  // freopen("maximum-sum.txt", "r", stdin);
  int n;
  cin >> n;

  int arr[n];
  for (int i = 0; i < n; ++i) {
    cin >> arr[i];
  }

  int sum[n];
  sum[0] = max(0, arr[0]);
  int best = 0;

  for (int k = 1; k < n; ++k) {
    sum[k] = max(sum[k - 1] + arr[k], arr[k]);
    best = max(best, sum[k]);
  }
  cout << best << BR;

  return EXIT_SUCCESS;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: WRONG ANSWER

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: WRONG ANSWER

Test 8

Verdict: WRONG ANSWER

Test 9

Verdict: WRONG ANSWER

Test 10

Verdict: WRONG ANSWER

Test 11

Verdict: WRONG ANSWER

Test 12

Verdict: WRONG ANSWER

Test 13

Verdict: WRONG ANSWER

Test 14

Verdict: WRONG ANSWER

Test 15

Verdict: WRONG ANSWER