#include "head.h"

void merge(int *arr, int *temp, int left, int mid, int right) {
    int i = left;      
    int j = mid + 1;   
    int k = left;      

    while (i <= mid && j <= right) {
        if (arr[i] <= arr[j]) {
            temp[k++] = arr[i++];
        } else {
            temp[k++] = arr[j++];
        }
    }

    while (i <= mid) temp[k++] = arr[i++];
    while (j <= right) temp[k++] = arr[j++];

    for (i = left; i <= right; i++) {
        arr[i] = temp[i];
    }
}

void merge_sort_recursive(int *arr, int *temp, int left, int right) {
    if (left < right) {
        int mid = left + (right - left) / 2;
        merge_sort_recursive(arr, temp, left, mid);
        merge_sort_recursive(arr, temp, mid + 1, right);
        merge(arr, temp, left, mid, right);
    }
}

void merge_sort(int *arr, int n) {
    int *temp = (int *)malloc(sizeof(int) * n);
    if (temp != NULL) {
        merge_sort_recursive(arr, temp, 0, n - 1);
        free(temp);
    }
}