Maximum sum

#include <bits/stdc++.h>

using namespace std;

//Definitions for quicker writing
#define REP(i,a,b) for (int i = a; i < b; i++)

//Typedefs for quicker writing
typedef long long ll;
typedef vector<int> vi;
typedef pair<int,int> pi;

int main() {
	//IO optimization

	ios::sync_with_stdio(0);
	cin.tie(0);
	
	//Input definition
	int n;

	//Read In
	cin >> n;
	
	ll arr[n];
	REP(i,0,n){
		cin >> arr[i];
	}
	
	ll best = 0, sum = 0;
	for (int k = 0; k < n; k++) {
		sum = max(arr[k], sum+arr[k]);
		best = max(best, sum);
	}

	cout << best << "\n";
		
	//Return
	return 0;

}

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: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: WRONG ANSWER

Test 13

Verdict: WRONG ANSWER

Test 14

Verdict: WRONG ANSWER

Test 15

Verdict: WRONG ANSWER