#include <stdio.h>
#include <stdlib.h>
#include<cstring>
void quicksort(int arr[],int left,int right) {
	if (left > right) {
		return;
	};
	int pivot = arr[left];
	int i = left;
	int j = right;
	while (i < j) {
		while (arr[j] >= pivot && i < j){
			j--;
		};
		while (arr[i] <= pivot && i < j) {
			i++;
		};
		if (i < j) {
			int temp = arr[i];
			arr[i] = arr[j];
			arr[j] = temp;
		};
	};
	arr[left] = arr[i];
	arr[i] = pivot;
	quicksort(arr, left, i - 1);
	quicksort(arr, i + 1, right);
};
void merge(int arr[], int left, int mid, int right) {
	int len1 = mid - left + 1;
	int len2 = right - mid;
	int *a = new int[len1+1];
	int *b = new int[len2+1];
	for (int i = 0; i < len1; i++) {
		a[i] = arr[left + i];
	};
	for (int j = 0; j < len2; j++) {
		b[j] = arr[mid + 1 + j];
	};
	int i = 0, j = 0;
	a[len1] = b[len2] = INT_MAX;
	for (int k = left; k <= right; k++) {
		if (a[i] < b[j]) {
			arr[k] = a[i];
			i++;
		}
		else {
			arr[k] = b[j];
			j++;
		}
	}
};
void mergesort(int arr[], int left, int right) {
	if (left < right) 
	{
		int mid = (left + right) / 2;
		mergesort(arr, left, mid);
		mergesort(arr, mid + 1, right);
		merge(arr, left, mid, right);
	}
};
void bubblesort(int arr[],int len) {
	for (int i = len - 1; i > 0; i--) {
		for (int j = 0; j <= i - 1; j++) {
			if (arr[j] > arr[j + 1]) {
				int temp = arr[j];
				arr[j] = arr[j + 1];
				arr[j + 1] = temp;
			}
		}
	}
};
int main()
{
	int arr[] = { 1,7,9,5,7 };
	//quicksort(arr, 0, 4);
	//mergesort(arr, 0, 4);
	bubblesort(arr, 5);
	for (int i = 0; i < 5; i++) {
		printf("%d", arr[i]);
	};
	system("pause");
	return 0;
}
 

其中有快速排序，氣泡排序和歸併排序。