[数据结构]——9大经典排序源码

1.插入排序

void Insertsort(int* a, int n)//插入排序
{
	for (int i = 0; i < n - 1; i++)
	{
		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;
		}
	}
}

2.希尔排序

void Shellsort(int* a, int n)//希尔排序
{
	int gap = n;
	while (gap > 1)
	{
		gap = gap / 3 + 1;
		for (int i = 0; i < n - gap; i++)
		{
			int end = i;
			int tmp = a[end + gap];
			while (end >= 0)
			{
				if (tmp < a[end])
				{
					a[end + gap] = a[end];
					end -= gap;
				}
				else
				{
					break;
				}
				a[end + gap] = tmp;
			}
		}
	}
}

3.直接选择排序

void Selectsort(int* a, int n)//直接选择排序
{
	int start = 0;
	int end = n - 1;
	
	while (start < end)
	{
		int min = start;
		int max = end;
		for (int i = start; i <= end; i++)
		{
			if (a[i] >= a[max])
			{
				max = i;
			}
			if (a[i] <= a[min])
			{
				min = i;
			}
		}
		Swap(&a[min], &a[start]);
		if (max == start)
		{
			max = min;
		}
		Swap(&a[max], &a[end]);

		end--; start++;
	}
}

4.堆排序

void AdJustdown(int* a, int size, int root)//向下调整算法
{
	int parent = root;
	int child = 2 * parent + 1;
	while (child < size)
	{
		if (a[child] < a[child + 1] && child + 1 < size)
		{
			++child;
		}

		if (a[parent] < a[child])
		{
			Swap(&a[parent], &a[child]);

			parent = child;
			child = 2 * parent + 1;
		}
		else
		{
			break;
		}
	}
}
void Heapsort(int* a, int n)//堆排序
{
	for (int i = (n - 2) / 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--;
	}
}

5.快速排序（左右指针法）

int Partsort(int* a, int begin, int end)//左右指针法
{
	int key = begin;
	while (begin < end)
	{
		while (begin < end && a[end] >= a[key])
		{
			--end;
		}
		while (begin < end && a[begin] <= a[key])
		{
			++begin;
		}

		Swap(&a[begin], &a[end]);
	}

	Swap(&a[key], &a[end]);

	return begin;
}
void Quicksort1(int* a, int begin, int end)//递归
{
	if (end <= begin)
	{
		return;
	}
	int index = Partsort(a, begin, end);
	Quicksort(a, begin, index - 1);
	Quicksort(a, index + 1, end);
}

6.快速排序（挖坑法）

int Partsort(int* a, int begin, int end)//挖坑法
{
	int mid = GetMidIndex(a, begin, end);
	Swap(&a[mid], &a[begin]);
	int key = a[begin];
	while (begin < end)
	{
		while (begin < end && a[end] >= key)
		{
			--end;
		}
		a[begin] = a[end];
		while (begin < end && a[begin] <= key)
		{
			++begin;
		}
		a[end] = a[begin];
	}
	a[begin] = key;

	return begin;
}
void Quicksort(int* a, int begin, int end)
{
	if (end <= begin)
	{
		return;
	}
	int index = Partsort(a, begin, end);
	Quicksort(a, begin, index - 1);
	Quicksort(a, index + 1, end);
}

7.快速排序（前后指针法）

int Partsort(int* a, int begin, int end)//前后指针法
{
	int key = begin;
	int cur = begin + 1;
	int pre = begin;
	while (cur <= end)
	{
		if (a[cur] <= a[key] && ++pre != cur)
		{
			Swap(&a[cur], &a[pre]);
		}
		++cur;
	}
	Swap(&a[key], &a[pre]);

	return pre;
}
void Quicksort(int* a, int begin, int end)
{
	if (end <= begin)
	{
		return;
	}
	int index = Partsort(a, begin, end);
	Quicksort(a, begin, index - 1);
	Quicksort(a, index + 1, end);
}

8.快速排序（非递归）

int Partsort(int* a, int begin, int end)
{
	int key = begin;
	int cur = begin + 1;
	int pre = begin;
	while (cur <= end)
	{
		if (a[cur] <= a[key] && ++pre != cur)
		{
			Swap(&a[cur], &a[pre]);
		}
		++cur;
	}
	Swap(&a[key], &a[pre]);

	return pre;
}
void Quicksort2(int* a, int begin, int end)//非递归
{
	Stack st;//博主前一次博客附带栈的实现
	StackInit(&st);
	StackPush(&st, end);
	StackPush(&st, begin);

	while (StackEmpty(&st))
	{
		int left = StackTop(&st);
		StackPop(&st);
		int right = StackTop(&st);
		StackPop(&st);

		int index = Partsort(a, left, right);

		if (index + 1 < right)
		{
			StackPush(&st, right);
			StackPush(&st, index + 1);
		}
		if (index - 1 > left)
		{
			StackPush(&st, index - 1);
			StackPush(&st, left);
		}
	}
}

9.冒泡排序

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

10.归并排序

void _MergeSort(int* a, int* tmp, int begin, int end)//归并排序
{

	if (begin >= end)
	{
		return;
	}
	int mid = begin + ((end - begin) >> 1);

	_MergeSort(a, tmp, begin, mid);
	_MergeSort(a, tmp, mid + 1, end);

	int begin1 = begin; int end1 = mid;
	int begin2 = mid + 1; int end2 = end;

	int index = 0;
	while (begin1 <= end1 && begin2 <= end2)
	{
		if (a[begin1] < a[begin2])
		{
			tmp[index++] = a[begin1++];
		}
		else
		{
			tmp[index++] = a[begin2++];
		}
	}

	while (begin1 <= end1)
	{
		tmp[index++] = a[begin1++];
	}
	while (begin2 <= end2)
	{
		tmp[index++] = a[begin2++];
	}	
	
	for (int i = 0; i < index; i++)
	{
		a[begin + i] = tmp[i];
	}
}
void MergeSort(int* a, int n)
{
	int* tmp = (int*)malloc(sizeof(int)*n);
	_MergeSort(a, tmp, 0, n - 1);
	free(tmp);
}

11.计数排序

void CountSort(int* a, int n)//计数排序
{
	int max = a[0];
	int min = a[0];
	for (int i = 0; i < n; i++)
	{
		if (a[i] > max)
		{
			max = a[i];
		}
		if (a[i] < min)
		{
			min = a[i];
		}
	}

	int range = max - min + 1;
	int* ans = (int*)malloc(sizeof(int)*range);
	memset(ans, 0, sizeof(int)*range);//把数组中的数字全部设置为0
	for (int j = 0; j < n; j++)
	{
		ans[a[j] - min]++;
	}
	int index = 0;
	for (int k = 0; k < range; k++)
	{
		while (ans[k]--)
		{
			a[index++] = k + min;
		}
	}
}