快排的模板

#include<cstdio>
const int maxn = 100005;
int arr[maxn]={0};
void quickSort(int *arr,int left,int right){
    int i = left,j =right;
    int mid = arr[(i+j)/2];
    while(i<=j){
        while(arr[i]<mid) i++;
        while(arr[j]>mid) j--;
        if(i<=j){
            int tmp;
            tmp = arr[i];
            arr[i] = arr[j];
            arr[j] = tmp;
            i++;
            j--;
        }
    }
    if(i<right) quickSort(arr,i,right);
    if(j>left) quickSort(arr,left,j);
} 
int main(){
    int n;
    scanf("%d",&n);
    for(int i =0;i<n;i++){
        scanf("%d",&arr[i]);
    }
    quickSort(arr,0,n-1);
    for(int i =0;i<n;i++){
        printf(i==0?"%d":" %d",arr[i]);
    }
    printf("\n");
    return 0;
}