Bank Account

#include <iostream>
#include <algorithm>

using namespace std;

int main() {
	int n, q;
	cin >> n; cin >> q;
	int arr[2*n];

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

	int a, b;
	for (int i=0; i<q; ++i) {
		cin >> a; cin >> b;
		//int s = n+a-1; int e = n+b-1;	//int e = 2*n-1;
		int sum = 0;
		// Naive implementation:
		/*while (s+1 < e) {
			sum += arr[s];
			sum += arr[e];
			++s; --e;
		}*/
		for (int j=n+a-1; j<n+b; ++j) {
			sum += arr[j];
		}
		cout << sum << "\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