40分，大佬帮忙看看

#include<stdio.h>
#include<time.h>
#include<stdlib.h>
int n, m;
int a[2000005], b[2000005], c[2000005], d[2000005];
void px(int r,int l)
{
	if (r >= l)
	{
		return;
	}
	int mid = rand() % (l - r + 1) + r;
	int tb = 0, tc = 0, td = 0;
	for (int i = 1; i <= m; i++)
	{
		if (a[i] < a[mid])
		{
			b[++tb] = a[i];
		}
		else if (a[i] > a[mid])
		{
			c[++tc] = a[i];
		}
		else
		{
			d[++td] = a[i];
		}
	}
	for (int i = 1; i <= tb; i++)
	{
		a[i + r - 1] = b[i];
	}
	for (int i = 1; i <= td; i++)
	{
		a[i + r + tb - 1] = d[i];
	}
	for (int i = 1; i <= tc; i++)
	{
		a[i + r + tb + td - 1] = c[i];
	}
	px(r, r + tb - 1);
	px(r + tb + td, l);
}
int main()
{
	srand((unsigned int)time(0));
	scanf("%d%d", &n, &m);
	for (int i = 1; i <= m; i++)
	{
		scanf("%d", &a[i]);
	}
	px(1, m);
	for (int i = 1; i <= m; i++)
	{
		printf("%d ", a[i]);
	}
	return 0;
}