归并排序--C语言实现

#include<stdio.h>

void merging(int *list1, int list1_size, int *list2, int list2_size)
{
	int temp[10];
	int i = 0, j = 0, k = 0;
	
	while ( i < list1_size && j < list2_size){    //比较后存进temp
		if (list1[i] < list2[j])
			temp[k++] = list1[i++];
		else
			temp[k++] = list2[j++];
	}
	while (i < list1_size){          //把剩下的数存进temp
		temp[k++] = list1[i++];
	}
	while (j < list2_size){
		temp[k++] = list2[j++];
	}
	for (int m = 0; m < (list1_size + list2_size); ++m){
		list1[m] = temp[m];
	}
}

void MergeSort(int k[], int n)    //k是数组的地址，n是数组长度
{
	if (n > 1){
		int *list1 = k;			             //序列1的开始
		int list1_size = n / 2;              //序列1长度
		int *list2 = k + n / 2;              //序列2的开始
		int list2_size = n - list1_size;     //序列2长度

		MergeSort(list1, list1_size);
		MergeSort(list2, list2_size);

		merging(list1, list1_size, list2, list2_size);
	}
}

int main()
{
	int i, a[10] = { 5, 6, 1, 4, 9, 2, 7, 3, 8, 0 };
	
	printf("排序前");
	for (int k = 0; k <= 9; ++k){    //输出排序前数组内元素
		printf("%d", a[k]);
		printf(" ");
	}
	printf("\n");

	MergeSort(a, 10);

	printf("排序后");
	for (int k = 0; k <= 9; ++k){   //输出排序后数组内元素
		printf("%d", a[k]);
		printf(" ");
	}
}