排序算法—歸併排序

#include<stdlib.h>    
#include<stdio.h>    


using namespace std;
 
void Merge(int* src,int * des,int low,int mid,int hight)
{
	int i = low;
	int j = mid + 1;
	int k = low;
	while (i<=mid&&j<=hight)//將小的梵高目的地中
	{
		if (src[i]<src[j])
		{
			des[k++] = src[i++];

		}
		else
		{
			des[k++] = src[j++];
		}
	}
	while (i<=mid)//若還剩幾個尾部元素，加到後面
	{
		des[k++] = src[i++];
	}
	while (j <= hight)
	{
		des[k++] = src[j++];
	}
}
//每次分爲兩路。當只剩下一個元素時，就不需要再劃分
void MSort(int* src, int* des, int low, int high,int max)
{
	if (low==high)
	{
		des[low] = src[low];
	}
	else//如果多個元素，進行兩路劃分
	{
		int mid = (low + high) / 2;

	    int* space = (int*)malloc(sizeof(int)*max);
		//遞歸進行兩路的劃分，當剩下一個元素的時候，遞歸劃分結束，然後開始merge歸併操作
		if (space!=NULL)
		{
			MSort(src,space,low,mid,max);
			MSort(src, space, mid+1, high, max);
			Merge(space, des, low, mid, high);

		}
		free(space);
	}
}
void MergeSort(int * arry,int count)
{
	MSort(arry,arry,0,count-1,count);
}
void main()
{
	int arry[] = { 12,20,45,25,35,1,2,54,52 };
	int count = sizeof(arry) / sizeof(*arry);
	printf("arry數組個數：%d\n", count);
	for (int i = 0; i < count; i++)
	{
		printf("%d ", arry[i]);
	}
	printf("\n排序之前");
	MergeSort(arry, count);
	for (int i = 0; i < count; i++)
	{
		printf("%d ", arry[i]);
	}
	printf("\n排序之後");
	system("pause");
}