Sorting books

input/code.cpp: In function 'll merge_sort(size_t, size_t, ll*, int)':
input/code.cpp:29:16: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   29 |   while (tmp_l <= k && tmp_k + 1 <= r) {
      |          ~~~~~~^~~~
input/code.cpp:29:34: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   29 |   while (tmp_l <= k && tmp_k + 1 <= r) {
      |                        ~~~~~~~~~~^~~~
input/code.cpp:40:16: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   40 |   for (; tmp_l <= k; tmp_l++, i++) {
      |          ~~~~~~^~~~
input/code.cpp:43:20: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   43 |   for (; tmp_k + 1 <= r; tmp_k++, i++) {
      |          ~~~~~~~~~~...

#include <bits/stdc++.h>
using namespace std;

#define PRINT_ARR(arr, n)                                                      \
  do {                                                                         \
    for (int i = 0; i < n; i++) {                                              \
      cout << arr[i] << " ";                                                   \
    }                                                                          \
    cout << "\n";                                                              \
  } while (0)

typedef long long ll;

ll merge_sort(size_t l, size_t r, ll *arr, int n) {
  if (l == r) {
    return 0;
  }

  ll sum = 0;
  size_t k = (l + r) / 2;
  sum += merge_sort(l, k, arr, n);
  sum += merge_sort(k + 1, r, arr, n);

  ll temp_arr[l + r];
  int tmp_l = l, tmp_k = k;

  int i = 0;

  while (tmp_l <= k && tmp_k + 1 <= r) {
    if (arr[tmp_l] > arr[tmp_k + 1]) {
      temp_arr[i] = arr[tmp_k + 1];
      tmp_k++;
      sum += k + 1 - tmp_l;
    } else {
      temp_arr[i] = arr[tmp_l];
      tmp_l++;
    }
    i++;
  }
  for (; tmp_l <= k; tmp_l++, i++) {
    temp_arr[i] = arr[tmp_l];
  }
  for (; tmp_k + 1 <= r; tmp_k++, i++) {
    temp_arr[i] = arr[tmp_k + 1];
  }

  for (int i = 0; i <= r - l; i++) {
    arr[l + i] = temp_arr[i];
  }
  return sum;
}

int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int n;
  cin >> n;
  ll nums[n];
  for (int i = 0; i < n; i++) {
    cin >> nums[i];
  }

  ll c = merge_sort(0, n - 1, nums, n);
  // for (int i = 0; i < n; i++) {
  //   cout << nums[i] << " ";
  // }
  // cout << "\n";
  cout << c << endl;

  return 0;
}

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

Test 22

Verdict: ACCEPTED

Test 23

Verdict: ACCEPTED

Test 24

Verdict: ACCEPTED

Test 25

Verdict: ACCEPTED

Test 26

Verdict: ACCEPTED

Test 27

Verdict: ACCEPTED

Test 28

Verdict: ACCEPTED

Test 29

Verdict: ACCEPTED

Test 30

Verdict: ACCEPTED

Test 31

Verdict: ACCEPTED

Test 32

Verdict: ACCEPTED

Test 33

Verdict: ACCEPTED

Test 34

Verdict: ACCEPTED

Test 35

Verdict: ACCEPTED

Test 36

Verdict: ACCEPTED

Test 37

Verdict: ACCEPTED

Test 38

Verdict: ACCEPTED

Test 39

Verdict: ACCEPTED

Test 40

Verdict: ACCEPTED

Test 41

Verdict: ACCEPTED

Test 42

Verdict: ACCEPTED

Test 43

Verdict: ACCEPTED

Test 44

Verdict: ACCEPTED

Test 45

Verdict: ACCEPTED

Test 46

Verdict: ACCEPTED

Test 47

Verdict: ACCEPTED

Test 48

Verdict: ACCEPTED

Test 49

Verdict: ACCEPTED

Test 50

Verdict: ACCEPTED

Test 51

Verdict: ACCEPTED

Test 52

Verdict: ACCEPTED

Test 53

Verdict: ACCEPTED

Test 54

Verdict: ACCEPTED

Test 55

Verdict: ACCEPTED

Test 56

Verdict: ACCEPTED

Test 57

Verdict: ACCEPTED

Test 58

Verdict: ACCEPTED

Test 59

Verdict: ACCEPTED

Test 60

Verdict: ACCEPTED

Test 61

Verdict: ACCEPTED

Test 62

Verdict: ACCEPTED

Test 63

Verdict: ACCEPTED

Test 64

Verdict: ACCEPTED

Test 65

Verdict: ACCEPTED

Test 66

Verdict: ACCEPTED

Test 67

Verdict: ACCEPTED

Test 68

Verdict: ACCEPTED

Test 69

Verdict: ACCEPTED

Test 70

Verdict: ACCEPTED

Test 71

Verdict: ACCEPTED