快速排序

#include <iostream>#include <algorithm>using namespace std;void quicksort(int a[],int low,int high){    if(low>=high)        return;        int first=low;        int last=high;        int key=a[first];        while(first<last){        while(last>first&&a[last]>=key){            --last;        }        a[first]=a[last];        while(first<last&&a[first]<=key){            ++first;        }        a[last]=a[first];        }        a[first]=key;        quicksort(a,low,first-1);        quicksort(a,first+1,high);}int main(){    int n;    while(cin>>n){        int a[n];        for(int i=0;i<n;i++)            cin>>a[i];        quicksort(a,0,n-1);        for(auto c:a)            cout<<c<<' ';            cout<<endl;    }    return 0;}