[原题链接](http://www.sdutacm.org/onlinejudge2/index.php/Home/Contest/contestproblem/cid/2019/pid/3491)
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int a[10000+10];
void qsort(int left,int right)
{
if(left>=right)return;
int i=left;
int j=right;
int key=a[left];
while(i<j)
{
while(i<j && a[j]>=key)j--;
a[i]=a[j];
while(i<j && a[i]<=key)i++;
a[j]=a[i];
}
a[i]=key;
qsort(left,i-1);
qsort(i+1,right);
}
int main()
{
int n;
while(~scanf("%d",&n))
{
for(int i=0;i<n;i++)
{
scanf("%d",&a[i]);
}
qsort(0,n-1);
for(int i=0;i<n;i++)
{
printf("%d",a[i]);
if(i==n-1)
{
printf("\n");
}
else printf(" ");
}
}
return 0;
}
STL
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <algorithm>
using namespace std;
int a[10000+10];
void qsort(int left,int right)
{
if(left>=right)return;
int i=left;
int j=right;
int key=a[left];
while(i<j)
{
while(i<j && a[j]>=key)j--;
a[i]=a[j];
while(i<j && a[i]<=key)i++;
a[j]=a[i];
}
a[i]=key;
qsort(left,i-1);
qsort(i+1,right);
}
int main()
{
int n;
while(~scanf("%d",&n))
{
for(int i=0;i<n;i++)
{
scanf("%d",&a[i]);
}
sort(a,a+n);
for(int i=0;i<n;i++)
{
printf("%d",a[i]);
if(i==n-1)
{
printf("\n");
}
else printf(" ");
}
}
return 0;
}