堆排序、归并排序

堆排序

#include <stdio.h>

void mySwap(int *a , int i , int j)      //½«Á½Êý½»»»
{
	int tmp = a[i];
	a[i] = a[j];
	a[j] = tmp;
}

 
//调整堆
void heapify(int *a , int index , int len) 
{
	int lindex = 2*index + 1; //左孩子结点下标
	int rindex = 2*index + 2; //右孩子结点下标

	int max = index;
	if (lindex < len && a[max] < a[lindex])
		max = lindex;
	if (rindex < len && a[max] < a[rindex])
		max = rindex;

	if (max != index)
	{
		mySwap(a , max , index);
		heapify(a , max , len);   //递归调整
	}
}


 void mySort(int *a , int len)
{
	//建堆：从非叶节点开始，把每一个结点调整为大顶堆
	int i ;
	for (i = len/2 - 1 ; i >= 0 ; i--)
	{
		heapify(a , i , len);
	}

	//排序
	int count = len;
	for(i = len-1 ; i >= 0 ; i--)
	{
		mySwap(a , 0 , i);  //堆顶元素和当前堆最后一个元素进行交换
		count--;
		heapify(a , 0 , count);
	}
}




void myPrint(int *a , int len)
{
	int i;
	for(i = 0 ; i < len ; i++)
	{
		printf("%4d",a[i]);
	}
	printf("\n");
}


int main()
{
	int a[] = {9, 8, 7, 6, 5, 4, 3, 2, 1, 0};
	int len = sizeof(a)/sizeof(a[0]);
	mySort(a , len);
	myPrint(a , len);
	return 0;
}

归并排序

#include <stdio.h>

void mySwap(int *a , int i , int j)      //½«Á½Êý½»»»
{
	int tmp = a[i];
	a[i] = a[j];
	a[j] = tmp;
}

 
void merge(int *a , int left , int mid , int right , int *tmp)
{
	int i = left;    //左半边数组下标
	int j = mid+1;   //右半边数组下标
	int k = 0;       //临时数组下标

	while (i <= mid && j <= right)
	{
		if (a[i] < a[j])
			tmp[k++] = a[i++];
		else
			tmp[k++] = a[j++];
	}

	while(i <= mid)
	{
		tmp[k++] = a[i++];
	}

	while(j <= right)
	{
		tmp[k++] = a[j++];
	}

	for(i = 0 ; i < k ; i++)
	{
		a[left+i] = tmp[i];
	}
}


void mergeSort(int *a , int left , int right , int *tmp)
{
	
	int mid = (left + right)/2;

	if(left < right)
	{
		mergeSort(a , left , mid , tmp);      //对左边数组进行归并排序
		mergeSort(a , mid+1 , right , tmp);   //对右边数组进行归并排序
		merge(a , left , mid , right , tmp);  //合并左右两个数组
	}
}




void myPrint(int *a , int len)
{
	int i;
	for(i = 0 ; i < len ; i++)
	{
		printf("%4d",a[i]);
	}
	printf("\n");
}


int main()
{
	int a[] = {9, 8, 7, 6, 5, 4, 3, 2, 1, 0};
	int len = sizeof(a)/sizeof(a[0]);

	int tmp[10];
	mergeSort(a , 0 , len-1 , tmp);
	myPrint(a , len);
	return 0;
}