排序算法

 /*
 sort.c(included kinds of sort algrithms)
 auther:yejing
 data:2014/07/23
 ver :1.0
*/

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

void swap(int* x, int* y)
{
	if(!x || !y)
		return;
	*x = *x + *y;
	*y = *x - *y;
	*x = *x - *y;

	return;
}

int partition(int front, int rear, int array[])
{
	if(front < rear)
	{
		int j;
		int i = front - 1;
		for(j = front; j < rear; j++)
			if(array[j] < array[rear])
			{
				i++;
				swap(&(array[j]), &(array[i]));
			}

		swap(&(array[i + 1]), &(array[rear]));
		return i + 1;
	}
}

void q_sort(int front, int rear, int array[])
{
	if(front < rear)
	{
		int middle = partition(front, rear, array);
		q_sort(front, middle - 1, array);
		q_sort(middle + 1, rear, array);
	}
	return;
}

void merge(int front, int middle, int rear, int array[])
{
	int i = front;
	int j = middle + 1;
	int k = 0;
	int tmp[1024];

	while(i <= middle && j <= rear)
		if(array[i] < array[j])
			tmp[k++] = array[j++];
		else
			tmp[k++] = array[i++];
	
	while(i <= middle)
		tmp[k++] = array[i++];

	while(j <= rear)
		tmp[k++] = array[j++];

	i = 0;
	for(i; i < k; ++i)
		array[front + i] = tmp[i];
	
	return;
}


void mergesort(int front , int rear, int array[])
{
	if(front < rear)
	{
		int middle = (front + rear)/2;
		mergesort(front, middle, array);
		mergesort(middle + 1, rear, array);
		merge(front, middle, rear, array);
	}
	return;
}

void insert_sort(int array[], int n)
{
	int i,j;
	int tmp;
	for(i = 1; i < n; ++i)
	{
		tmp = array[i];
		for(j = i; j > 0 && array[j - 1] < tmp; --j) 
			array[j] = array[j - 1];

		array[j] = tmp;
	}
}

int main(int argc, char* argv[])
{
	int array[19] = {1, 2, 3, 4, 5, 6, 6, 7, 4, 34, 23, 23, 54, 523, 1, 23, 45, 657, 879};
	printf("please chose the sort algrithm:\n");
	printf("1-->insert_sort   2-->mergesort   3-->qsort\n");
	int pattern;
	scanf("%d", &pattern);

	if(pattern == 1)
		insert_sort(array, 19);
	else if(pattern == 2)
		mergesort(0, 18, array);
	else if(pattern == 3)
		q_sort(0, 18, array);
	else
		printf("pattern do not support\n");

	
	int i;
	for(i = 0; i < 19; ++i)
		printf("%d ", array[i]);
	printf("\n");
	pause();
}