Candies

#include <iostream>

#define ll long long

using namespace std;

int n;
int c[101010];
ll r[101010];
ll sum;

int main() {
	cin >> n;
	for (int i=0;i<n;i++) {
		cin >> c[i];
		sum += c[i];
	}
	if (sum%2) {
		cout << "QAQ\n";
		return 0;
	}
	sum = 0;
	for (int i=0;i<n/2;i++) {
		r[i] = c[i]-c[i+n/2];
		r[i+n/2] = -r[i];
	}
	for (int i=1;i<n;i++) {
		r[i] += r[i-1];
	}
	for (int i=n/2;i<n;i++) {
		sum += abs(r[i]-r[i-n/2]);
	}
	cout << sum/2 << "\n";
}

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

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: ACCEPTED