7大排序算法的實現

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

void BubbleSort1 (int n, int *array)	/*little > big*/
{
	int i, j;
	for (i=0; i<n-1; i++)
	{
		for (j=n-1; j>i; j--)
		{
			if (array[j] < array[j-1])
			{
				int temp = array[j];
				array[j] = array[j-1];
				array[j-1] = temp;
			}
		}
	}
}

void BubbleSort2 (int n, int *array)
{
	int i, j, flag=1;	/*flag=1表示需要繼續冒泡*/
	for (i=0; i<n-1 && flag; i++)
	{
		flag = 0;
		for (j=n-1; j>i; j--)
		{
			if (array[j] < array[j-1])
			{
				int temp = array[j];
				array[j] = array[j-1];
				array[j-1] = temp;
				flag = 1;
			}
		}
	}
}

void SelectSort (int n, int *array)
{
	int i, j, min;
	for (i=0; i<n-1; i++)
	{
		min = i;
		for (j=i+1; j<n; j++)
		{
			if (array[min] > array[j])
				min = j;
		}
		int temp = array[min];
		array[min] = array[i];
		array[i] = temp;
	}
}

void InsertSort (int n, int*array)
{
	int i, j;
	for (i=1; i<n; i++)
	{
		if (array[i] < array[i-1])	/*是否需要插入*/
		{
			int key = array[i];	//哨兵
			for (j = i-1;j>=0 && array[j] > key; j--)
			{
				array[j+1] = array[j];
			}
			/*循環結束時array[j]<=key,將key插入到j+1處*/
			array[j+1] = key;
		}
	}
}

/*分組插入排序*/
void ShellSort (int n, int *array)
{
	int i, j;
	int increment;
	for (increment=n/2; increment > 0; increment /= 2)
	{
		for (i=0; i<increment; i++)		/*下面對一組序列進行插入排序*/
		{
			for (j=i+increment; j<n; j+=increment)
			{
				if (array[j] < array[j-increment])
				{
					int key = array[j];
					int k;
					for (k=j-increment; k>=0 && array[k]>key; k -= increment)
					{
						array[k+increment] = array[k];
					}
					array[k+increment] = key;
				}
			}
		}
	}
}

/*分治法*/
void QuickSort (int left, int right, int *array)
{
	if(left>=right)
		return ;
	int i=left, j=right;
	int key=array[i];
	while (i<j)
	{
		while (i<j && array[j]>=key)
			j--;
		array[i] = array[j];
		while (i<j && array[i]<=key)
			i++;
		array[j] = array[i];
	}
	array[i] = key;
	QuickSort(left, i-1, array);
	QuickSort(i+1, right, array);
}

/*array[start+1] ~ array[end]已經滿足堆的定義，調整使得array[start] ~ array[end]滿足堆定義*/
void HeapAdjust (int start, int end, int array[])
{
	int i;
	int temp = array[start];	/*產生第一個空白*/
	for (i=2*start+1; i<=end; i=2*i+1)		/*每次循環時空白節點爲array[(i-1)/2]*/
	{
		if (i<end && array[i] < array[i+1])		/*在左右孩子中尋找較大值*/
			i++;
		if (array[i] > temp)
			array[(i-1)/2] = array[i];
		else
			break;
	}
	array[(i-1)/2] = temp;		/*插入原來的temp到空白處*/
}
void HeapSort (int n, int array[])
{
	int i;
	for (i=(n-2)/2; i>=0; i--)		/*構造大頂堆*/
		HeapAdjust(i, n-1, array);

	for (i=n-1; i>0; i--)
	{
		int t = array[i];	/*將根節點交換到數組末端*/
		array[i] = array[0];
		array[0] = t;

		HeapAdjust(0, i-1, array);	/*重新調整堆*/
	}
}

/*array[s…m]和array[m+1…t]均已各自有序，合併使得array[s…t]有序*/
void Merge(int s, int m, int t, int *array)
{
	int temp[t-s+1];
	int i=s, j=m+1, k=0;
	while(i<=m && j<=t)
	{
		if(array[i] < array[j])
			temp[k++] = array[i++];
		else
			temp[k++] = array[j++];
	}
	while(i<=m)
		temp[k++] = array[i++];
	while(j<=t)
		temp[k++] = array[j++];

	for(i=s, k=0; i<=t && k<=t-s; i++, k++)
	{
		array[i] = temp[k];
	}
}
void MSort (int s, int t, int *array)	/*遞歸調用*/
{
	if(s == t)
		return ;
	int m = (s+t)/2;
	MSort(s, m, array);
	MSort(m+1, t, array);
	Merge(s, m, t, array);
}
void MergeSort1(int n, int *array)
{
	MSort(0, n-1, array);
}
void MergeSort2(int n, int *array)	/*非遞歸實現歸併排序*/
{
	int k, i;
	for (k=1; 2*k<n; k *= 2)	/*設置每段待歸併的有序序列的長度：1,2,4,8,16……*/
	{
		for (i=0; i+k-1<n; i += 2*k)	/*考慮待歸併的左右兩段序列，[i+k-1]是左序列末尾元素下標*/
		{								/*[end=i+2*k-1]是右序列末尾元素下標,end不應該超過n-1*/
			int end=i+2*k-1;
			if(end > n-1)
				end = n-1;
			Merge(i, i+k-1, end, array);
		}
	}
}


int main()
{
	long start, stop;
	int n;
	printf("下面比較幾個時間複雜度爲NlogN的排序算法效率高低,其他3個低效率的排序就不考慮了\n");
	printf("輸入待排序數量（int類型表示,在我的機器上超過100萬就可能溢出）:\n");
	scanf("%d", &n);
	int a[n], i;

	for(i=0; i<n; i++)
		a[i] = rand()%n;
	start = clock();
	ShellSort(n, a);
	stop = clock();
	printf("希爾排序%d個數據花費時間爲： %ldms\n", n, (stop-start)*1000/CLOCKS_PER_SEC);

	for(i=0; i<n; i++)
		a[i] = rand()%n;
	start = clock();
	HeapSort(n, a);
	stop = clock();
	printf("堆排序%d個數據花費時間爲： %ldms\n", n, (stop-start)*1000/CLOCKS_PER_SEC);

	for(i=0; i<n; i++)
		a[i] = rand()%n;
	start = clock();
	MergeSort1(n, a);
	stop = clock();
	printf("遞歸式歸併排序%d個數據花費時間爲： %ldms\n", n, (stop-start)*1000/CLOCKS_PER_SEC);

	for(i=0; i<n; i++)
		a[i] = rand()%n;
	start = clock();
	MergeSort2(n, a);
	stop = clock();
	printf("非遞歸式歸併排序%d個數據花費時間爲： %ldms\n", n, (stop-start)*1000/CLOCKS_PER_SEC);

	for(i=0; i<n; i++)
		a[i] = rand()%n;
	start = clock();
	QuickSort(0, n-1, a);
	stop = clock();
	printf("快速排序%d個數據花費時間爲： %ldms\n", n, (stop-start)*1000/CLOCKS_PER_SEC);

/*	for(i=0; i<n; i++)
	{
		printf("%d ", a[i]);
	}
*/
	return 0;
}