quickSort - 快速排序

#include <iostream>
#include <string>
#include <cstring>
#include <cstdlib>
#include <cstdio>
#include <cmath>
#include <vector>
#include <stack>
#include <deque>
#include <queue>
#include <bitset>
#include <list>
#include <map>
#include <set>
#include <iterator>
#include <algorithm>
#include <functional>
#include <utility>
#include <sstream>
#include <climits>
#include <cassert>
#define BUG puts("here!!!");

using namespace std;

void quickSort(int a[], int left, int right) {
    if(left < right) {
        int l = left, r = right, x = a[l];
        while(1) {
            while(l < r && a[r] >= x) r--;
            while(l < r && a[l] <= x) l++;
            if(l >= r) break;
            swap(a[r], a[l]);
        }
        swap(a[left], a[l]);
        quickSort(a, left, l-1);
        quickSort(a, l+1, right);
    }
}
int main() {
    int a[] = {8, 5, 4, 9, 2, 3, 6};
    quickSort(a, 0, 6);
    for(int i = 0; i <= 6; i++) {
        cout << a[i] << ' ';
    }
    cout << endl;
    return 0;
}

// 用例2 ： 6, 5, 8, 6, 9, 1, 2