编辑代码

#include <stdio.h>

void merge(int arr[], int left[], int leftSize, int right[], int rightSize) {
    int i = 0;
    int j = 0;
    int k = 0;
    
    while (i < leftSize && j < rightSize) {
        if (left[i] <= right[j]) {
            arr[k++] = left[i++];
        } else {
            arr[k++] = right[j++];
        }
    }
    
    while (i < leftSize) {
        arr[k++] = left[i++];
    }
    while (j < rightSize) {
        arr[k++] = right[j++];
    }
}

void mergeSort(int arr[], int size) {
    if (size < 2) {
        return;
    }
    
    int mid = size / 2;
    
    int left[mid];
    int right[size - mid];
    
    for (int i = 0; i < mid; i++) {
        left[i] = arr[i];
    }
    for (int i = mid; i < size; i++) {
        right[i - mid] = arr[i];
    }
    
    mergeSort(left, mid);
    mergeSort(right, size - mid);
    
    merge(arr, left, mid, right, size - mid);
}

void printArray(int array[], int arrLen) {
    for (int i = 0; i < arrLen; ++i) {
        printf("%d ", array[i]);
    }
    printf("\n");
}


int main() {
    int arr1[] = {12, 5, 13, 10, 9, 20, 5};
    int size1 = sizeof(arr1) / sizeof(arr1[0]);
    printf("测试一：归并数组前：");
    printArray(arr1, size1);
    
    printf("测试一：归并排序后：");
    mergeSort(arr1, size1);
    printArray(arr1, size1);

    int arr2[] = {9, 13, 6, 1, -1, 4, 22, 11};
    int size2 = sizeof(arr2) / sizeof(arr2[0]);
    printf("测试二：归并数组前：");
    printArray(arr2, size2);
    
    printf("测试二：归并排序后：");
    mergeSort(arr2, size2);
    printArray(arr2, size2);

    int arr3[] = {-1, -9, -3, -2, -8, -11};
    int size3 = sizeof(arr3) / sizeof(arr3[0]);
    printf("测试三：归并数组前：");
    printArray(arr3, size3);
    
    printf("测试三：归并排序后：");
    mergeSort(arr3, size3);
    printArray(arr3, size3);
    return 0;
}