Lucky prefixes

input/code.cpp: In function 'int main()':
input/code.cpp:26:33: warning: comparison of integer expressions of different signedness: 'ull' {aka 'long unsigned int'} and 'll' {aka 'long int'} [-Wsign-compare]
   26 |             for (ull it = 0; it < b-a; it++) {
      |                              ~~~^~~~~

#include <bits/stdc++.h>

using namespace std;

typedef int64_t ll;
typedef uint64_t ull;

int main() {
    ull n; ull q;
    cin >> n >> q;

    vector<ll> arr (n);

    for (ull i = 0; i < n; i++) {
        ll num;
        cin >> num;
        arr.at(i) = num;
    }

    for (ull i = 0; i < q; i++) {
        int type; ll a; ll b;
        cin >> type >> a >> b;
        if (type == 2) {
            bool lucky = true;
            ll summa = 0;
            for (ull it = 0; it < b-a; it++) {
                summa += arr[a-1+it];
                if (summa<0) {
                    lucky = false;
                    break;
                }
            }
            cout << (lucky ? "YES" : "NO") << endl;
        } else {
            arr.at(a-1) = b;
        }
    }

}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: TIME LIMIT EXCEEDED

Test 3

Verdict: WRONG ANSWER

Test 4

Verdict: WRONG ANSWER

Test 5

Verdict: ACCEPTED

Test 6

Verdict: WRONG ANSWER

Test 7

Verdict: WRONG ANSWER

Test 8

Verdict: WRONG ANSWER

Test 9

Verdict: ACCEPTED

Test 10

Verdict: WRONG ANSWER

Test 11

Verdict: WRONG ANSWER

Test 12

Verdict: ACCEPTED

Test 13

Verdict: WRONG ANSWER

Test 14

Verdict: WRONG ANSWER

Test 15

Verdict: WRONG ANSWER

Test 16

Verdict: ACCEPTED