编辑代码

#include<stdio.h>
#include<stdlib.h>
    int K[] ={11,9,3,20,56,32};
	int sz = sizeof(K) / sizeof(K[0]);
void Merge(int a[], int low, int mid, int high) {
	int* b = (int*)malloc(sz*sizeof(int));
	int i, j, k;    //i,j指向辅助数组中的两个序列，k指向原数组中元素应该在的位置
	for (k = low; k <= high; k++)         //把两个子序列复制到辅助数组中，范围分别是[low,mid], [mid+1,high]
		b[k] = a[k];
	for (i = low, j = mid + 1, k = i; i <= mid && j <= high; k++) {
		if (b[i] < b[j])
			a[k] = b[i++];
		else
			a[k] = b[j++];
	}
	while (i <= mid)  a[k++] = b[i++];                   //最后只可能刚好比较完或剩下较长的数组，此时较长的数组中的元素都比排好序的元素大，直接复制过去即可
	while (j <= high) a[k++] = b[j++];					// 两个while循环只可能执行一个
}
void Merge_Sort(int a[], int low, int high) {          //low和high指明了归并排序的序列的范围
	if (low < high) {          //跳出递归的条件
		int mid = (low + high) / 2;                   //两两对半拆分
		Merge_Sort(a, low, mid);                      
		Merge_Sort(a, mid + 1, high);
		Merge(a, low, mid, high);
	}
}

int main() {
	Merge_Sort(K, 0, sz-1);
	for (int i = 0; i < sz; i++)
		printf("%d\t", K[i]);
}