排序算法的C语言实现C代码

总结并编写了部分常用的排序算法，包括前向、后向冒泡排序、简单选择排序、直接插入排序、希尔排序、堆排序、并归排序和快速排序。
具体的原理请参考《大话数据结构》。

#include
#include

//从前向后冒泡 =======================================================
void bubble(int arr[], int n)
{
     
	for (int i = 0; i < n - 1; i++)
	{
     
		for (int j = 0; j < n - 1 - i; j++)
		{
     
			if (arr[j] > arr[j + 1])
			{
     
				int temp = arr[j];
				arr[j] = arr[j + 1];
				arr[j + 1] = temp;
			}
		}
	}
}

//从后向前冒泡
void bubble2(int arr[], int n)
{
     
	for (int i = 0; i < n - 1; i++)
	{
     
		for (int j = n - 1; j > i; j--)
		{
     
			if (arr[j - 1] > arr[j])
			{
     
				int temp = arr[j];
				arr[j] = arr[j - 1];
				arr[j - 1] = temp;
			}
		}
	}
}

//选择排序 =======================================================
void selectsort(int arr[], int n)
{
     
	for (int i = 0; i < n ; i++)
	{
     
		int index = i;
		for (int j = i + 1; j < n; j++)
		{
     
			if (arr[index] > arr[j])
				index = j;
		}
		if (i != index)
		{
     
			int temp = arr[i];
			arr[i] = arr[index];
			arr[index] = temp;
		}
	}
}


//插入排序 =======================================================
void insertionsort(int arr[], int n)
{
     
	for (int i = 1; i < n; i++)
	{
     
		int temp = arr[i];
		while (i >= 0 && arr[i - 1] > temp)
		{
     
			arr[i] = arr[i - 1];
			i--;
		}
		arr[i] = temp;
	}
}

//希尔排序 =======================================================
void shellsort(int arr[], int n)
{
     
	int gap = n;
	int temp;
	int i, j;
	do
	{
     
		gap = gap / 2;
		for (i = gap; i < n; i++)
		{
     
			if (arr[i] < arr[i - gap])
			{
     
				temp = arr[i];
				for (j = i - gap; j >= 0 && temp < arr[j]; j -= gap)
					arr[j + gap] = arr[j];
				arr[j + gap] = temp;
			}
		}
	} while (gap > 1);
}

//堆排序 =======================================================
void heapadjust(int arr[], int s, int m)
{
     
	int j;
	int temp = arr[s];
	for (j = (2*s)+1; j < m; j *= 2)
	{
     
		if (j < m && arr[j] < arr[j + 1]) 
			j++;
		if (temp > arr[j])
			break;
		arr[s] = arr[j]; 
		s = j;
	}
	arr[s] = temp;
}

void heapsort(int arr[], int n)
{
     
	int i;
	for (i = (n/2)-1; i >= 0; i--)
		heapadjust(arr, i, n);
	for (i = 0; i < n; i++)
	{
     
		int temp = arr[0];
		arr[0] = arr[n-1-i];
		arr[n-1-i] = temp;
		heapadjust(arr, 0, n-1-i-1);
	}
}

//归并排序
void merge(int arr[], int start, int mid, int end) 
{
     
	int* result = (int*)malloc((end + 1) * sizeof(int));
	int k = 0;
	int i = start;
	int j = mid + 1;
	while (i <= mid && j <= end) {
     
		if (arr[i] < arr[j]) {
     
			result[k++] = arr[i++];
		}
		else {
     
			result[k++] = arr[j++];
		}
	}
	if (i == mid + 1) {
     
		while (j <= end)
			result[k++] = arr[j++];
	}
	if (j == end + 1) {
     
		while (i <= mid)
			result[k++] = arr[i++];
	}
	for (j = 0, i = start; j < k; i++, j++) {
     
		arr[i] = result[j];
	}
	free(result);
}

void mergeSort(int arr[], int start, int end)
{
     
	if (start >= end)
		return;
	int mid = (start + end) / 2;
	mergeSort(arr, start, mid);
	mergeSort(arr, mid + 1, end);
	merge(arr, start, mid, end);
}

//快速排序 =======================================================
int fun(int arr[], int low, int high)
{
     
	int key;
	key = arr[low];
	while (low < high)
	{
     
		while (low < high && arr[high] >= key)
			high--;
		if (low < high)
			arr[low++] = arr[high];
		while (low < high && arr[low] <= key)
			low++;
		if (low < high)
			arr[high--] = arr[low];
	}
	arr[low] = key;
	return low;
}
void quicksort(int arr[], int start, int end)
{
     
	int pos;
	if (start < end)
	{
     
		pos = fun(arr, start, end);
		quicksort(arr, start, pos - 1);
		quicksort(arr, pos + 1, end);
	}
}

//=======================================================
//=======================================================
int main()
{
     
	int arr[] = {
      9,5,1,4,0,7,2,6,8,3 };
	//冒泡排序
	//bubble(arr, 10);
	//bubble2(arr, 10);
	//选择排序
	//selectsort(arr, 10);
	//插入排序
	//insertionsort(arr, 10);
	//希尔排序
	//shellsort(arr, 10);
	//堆排序
	//heapsort(arr, 10);
	//归并排序
	//mergeSort(arr, 0, 9);
	//快速排序
	quicksort(arr, 0, 9);

	for (int i = 0; i < 10; i++)
		printf("%d ", arr[i]);

	return 0;
}