怎么用C语言编写归并排序

以下是使用C语言编写归并排序的示例代码：

#include <stdio.h>

void merge(int arr[], int left, int mid, int right) {
    int i, j, k;
    int n1 = mid - left + 1;
    int n2 = right - mid;
    int L[n1], R[n2];

    for (i = 0; i < n1; i++) {
        L[i] = arr[left + i];
    }
    for (j = 0; j < n2; j++) {
        R[j] = arr[mid + 1 + j];
    }

    i = 0;
    j = 0;
    k = left;
    while (i < n1 && j < n2) {
        if (L[i] <= R[j]) {
            arr[k++] = L[i++];
        } else {
            arr[k++] = R[j++];
        }
    }

    while (i < n1) {
        arr[k++] = L[i++];
    }

    while (j < n2) {
        arr[k++] = R[j++];
    }
}

void merge_sort(int arr[], int left, int right) {
    if (left < right) {
        int mid = (left + right) / 2;
        merge_sort(arr, left, mid);
        merge_sort(arr, mid + 1, right);
        merge(arr, left, mid, right);
    }
}

int main() {
    int arr[] = {38, 27, 43, 3, 9, 82, 10};
    int n = sizeof(arr) / sizeof(arr[0]);
    int i;

    printf("Original array: \n");
    for (i = 0; i < n; i++) {
        printf("%d ", arr[i]);
    }
    printf("\n");

    merge_sort(arr, 0, n - 1);

    printf("Sorted array: \n");
    for (i = 0; i < n; i++) {
        printf("%d ", arr[i]);
    }
    printf("\n");

    return 0;
}

运行结果：

Original array:
38 27 43 3 9 82 10
Sorted array:
3 9 10 27 38 43 82