排序汇总(插入排序、选择排序、交换排序、归并排序)

Test.c

#define _CRT_SECURE_NO_WARNINGS 1
#include "Sort.h"

void TestInsertSort()
{
	int arr[] = { 9, 1, 2, 5, 7, 4, 8, 6, 3, 5 };
	int sz = sizeof(arr) / sizeof(arr[0]);
	InsertSort(arr, sz);
	PrintArray(arr, sz);
}

void TestShellSort()
{
	int arr[] = { 9, 1, 2, 5, 7, 4, 8, 6, 3, 5 };
	int sz = sizeof(arr) / sizeof(arr[0]);
	ShellSort(arr, sz);
	PrintArray(arr, sz);
}

void TestBubbleSort()
{
	int arr[] = { 9, 1, 2, 5, 7, 4, 8, 6, 3, 5 };
	int sz = sizeof(arr) / sizeof(arr[0]);
	BubbleSort(arr, sz);
	PrintArray(arr, sz);
}

void TestQuickSort()
{
	int arr[] = { 9, 1, 2, 5, 7, 4, 8, 6, 3, 5 };
	int sz = sizeof(arr) / sizeof(arr[0]);
	QuickSort(arr, 0, sz - 1);
	PrintArray(arr, sz);
}

void TestSelectSort()
{
	int arr[] = { 9, 1, 2, 5, 7, 4, 8, 6, 3, 5 };
	int sz = sizeof(arr) / sizeof(arr[0]);
	SelectSort(arr, 0, sz - 1);
	PrintArray(arr, sz);
}

void TestHeapSort()
{
	int arr[] = { 9, 1, 2, 5, 7, 4, 8, 6, 3, 5 };
	int sz = sizeof(arr) / sizeof(arr[0]);
	HeapSort(arr, sz);
	PrintArray(arr, sz);
}

void TestMergeSort()
{
	int arr[] = { 9, 1, 2, 5, 7, 4, 8, 6, 3, 5 };
	int sz = sizeof(arr) / sizeof(arr[0]);
	MergeSort(arr, 0, sz - 1);
	PrintArray(arr, sz);
}


int main()
{
	//TestInsertSort();
	//TestShellSort();
	//TestBubbleSort();
	//TestQuickSort();
	//TestSelectSort();
	//TestHeapSort();
	TestHeapSort();

	return 0;
}

Sort.h

#define _CRT_SECURE_NO_WARNINGS 1
#include 
#include 
#include 
#include 

void PrintArray(int* a, int n);

//插入排序
void InsertSort(int* a, int n);
void ShellSort(int* a, int n);

//交换排序
void BubbleSort(int* a, int n);
void QuickSort(int* a, int begin, int end);

//选择排序
void SelectSort(int* a, int begin, int end);
void HeapSort(int* a, int n);

//归并排序
void MergeSort(int* a, int begin, int end);

Sort.c

#define _CRT_SECURE_NO_WARNINGS 1
#include "Sort.h"

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

void InsertSort(int* a, int n)
{
	assert(a);
	//多趟插入排序

	for (int i = 0; i < n - 1; i++)
	{
		//单趟插入排序
		int end = i;
		int tmp = a[end + 1];
		while (end >= 0)
		{
			if (tmp < a[end])
			{
				a[end + 1] = a[end];
				end--;
			}
			else
			{
				break;
			}
		}
		a[end + 1] = tmp;
	}

}

void ShellSort(int* a, int n)
{
	assert(a);
	int gap = n;
	while (gap > 1)
	{
		//gap逐渐变化
		gap = gap / 3 + 1;

		//gap组数据交替插入排序
		for (int i = 0; i < n - gap; i++)
		{
			//单个间距为gap的数插入已经排好序的区间内
			int end = i;
			int tmp = a[end + gap];
			while (end >= 0)
			{
				if (tmp < a[end])
				{
					a[end + gap] = a[end];
					end -= gap; //注意这儿容易写错为：end--;
				}
				else
				{
					break;
				}
			}
			a[end + gap] = tmp;
		}
	}

}

static void Swap(int* a, int* b)
{
	int tmp = *a;
	*a = *b;
	*b = tmp;
}

void BubbleSort(int* a, int n)
{
	assert(a);
	for (int i = 0; i < n; i++)
	{
		for (int j = 0; j < n - 1 - i; j++)
		{
			if (a[j + 1] < a[j])
			{
				Swap(&a[j + 1], &a[j]);
			}
		}
	}

}

static int GetMidIndex(int* a, int begin, int end)
{
	int midi = (begin + end) / 2;
	if (a[begin] < a[midi])
	{
		if (a[begin] > a[end])
		{
			return begin;
		}
		else if (a[midi] < a[end])
		{
			return midi;
		}
		else // a[begin]a[end]
		{
			return end;
		}

	}
	else  //a[begin]>a[midi]
	{
		if (a[begin] < a[end])
		{
			return begin;
		}
		else if (a[midi] > a[end])
		{
			return midi;
		}
		else
		{
			return end;
		}
	}
}


//双指针法
int QuickSortPart1(int* a, int begin, int end)
{
	int prev = begin;
	int cur = begin + 1;
	int keyi = begin;
	//加入“三数取中”的优化（避免选到的keyi对应的值为最大值或最小值）
	int midi = GetMidIndex(a, begin, end);
	Swap(&a[keyi], &a[midi]);

	while (cur <= end)
	{
		if (a[cur] < a[keyi])
		{
			prev++;
			Swap(&a[prev], &a[cur]);
		}
		cur++;
	}
	Swap(&a[prev], &a[keyi]);
	keyi = prev;

	return keyi;
}

void QuickSort(int* a, int begin, int end)
{
	if (begin >= end)
	{
		return;
	}

	//小区间优化，避免递归次数过多造成栈溢出并提升效率
	if (end - begin > 10)
	{
		int keyi = QuickSortPart1(a, begin, end);
		//[begin,keyi-1][keyi+1,end]
		QuickSort(a, begin, keyi - 1);
		QuickSort(a, keyi + 1, end);
	}
	else
	{
		InsertSort(a + begin, end - begin + 1);
	}
}


void SelectSort(int* a, int begin, int end)
{
	assert(a);
	while (begin < end)
	{
		int mini = begin, maxi = end;
		for (int i = begin; i <= end; i++)
		{
			if (a[i] < a[mini])
			{
				mini = i;
			}
			if (a[i] > a[maxi])
			{
				maxi = i;
			}
		}
		Swap(&a[mini], &a[begin]);
		if (begin == maxi)
		{
			maxi = mini;
		}
		Swap(&a[maxi], &a[end]);

		begin++;
		end--;
	}
}


static void AdjustDown(int* a, int size, int parent)
{
	int child = parent * 2 + 1; //默认较大的孩子为左孩子
	while (child < size)
	{
		if (child + 1 < size && a[child + 1] > a[child]) //如果右孩子存在且大于左孩子
		{
			child++;
		}

		if (a[child] > a[parent])
		{
			Swap(&a[child], &a[parent]);
			//下一代父子关系的调整
			parent = child;
			child = parent * 2 + 1;
		}
		else
		{
			break;
		}

	}
}

void HeapSort(int* a, int n)
{
	for (int i = (n - 1 - 1) / 2; i >= 0; i--)
	{
		AdjustDown(a, n, i);
	}

	int end = n - 1;
	while (end > 0)
	{
		Swap(&a[0], &a[end]);
		AdjustDown(a, end, 0);
		end--;
	}

}

void _MergeSort(int* a, int begin, int end, int* tmp)
{
	if (begin >= end)
	{
		return;
	}

	//递归，完成左右区间的划分
	int mid = (begin + end) / 2;
	//[begin,mid][mid+1,end]
	_MergeSort(a, begin, mid, tmp);
	_MergeSort(a, mid + 1, end, tmp);

	//并归，完成左右区间的排序
	int begin1 = begin, end1 = mid;
	int begin2 = mid + 1, end2 = end;
	int i = begin1;
	while (begin1 <= end1 && begin2 <= end2)
	{
		if (a[begin1] < a[begin2])
		{
			tmp[i++] = a[begin1++];
		}
		else
		{
			tmp[i++] = a[begin2++];
		}
	}

	while (begin1 <= end1)
	{
		tmp[i++] = a[begin1++];
	}
	while (begin2 <= end2)
	{
		tmp[i++] = a[begin2++];
	}

	//重新copy到原数组
	memcpy(a + begin, tmp + begin, (end - begin + 1));
}

void MergeSort(int* a, int begin, int end)
{
	int* tmp = (int*)malloc(sizeof(int) * (end - begin + 1));
	if (NULL == tmp)
	{
		printf("malloc fail");
		exit(-1);
	}

	_MergeSort(a, begin, end, tmp);

	free(tmp);
	tmp = NULL;
}