归并排序算法

归并排序算法

#include<stdio.h>
#define ArrLen 20
void printList(int arr[], int len) {
	int i;
	for (i = 0; i < len; i++) {
		printf("%d\t", arr[i]);
	}
}
void merge(int arr[], int start, int mid, int end) {
	int result[ArrLen];
	int k = 0;
	int i = start;
	int j = mid + 1;

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

	if (i == mid + 1) {
		while (j <= end)
			result[k++] = arr[j++];
	}
	if (j == end + 1) {
		while (i <= mid)
			result[k++] = arr[i++];
	}
	for (j = 0, i = start; j < k; i++, j++) {
		arr[i] = result[j];
	}
}

void mergeSort(int arr[], int start, int end) {
	if (start >= end)
		return;
	int mid = (start + end) / 2;
	mergeSort(arr, start, mid);
	mergeSort(arr, mid + 1, end);
	merge(arr, start, mid, end);
}

int main()
{

    int arr[8];
    int i;

    // 初始化随机数种子
    srand(time(NULL));

    // 生成随机数并将其添加到数组中
    for (i = 0; i < 8; i++) {
        arr[i] = rand() % 100;
    }

    // 打印数组元素
    printf("随机生成的数组为: ");
    for (i = 0; i < 8; i++) {
        printf("%d ", arr[i]);
    }
        printf("\n经过排序后得到的是");



	mergeSort(arr, 0, 9);
	printList(arr, 10);
	system("pause");
	return 0;
}