11352071	nblt	2388	Accepted	244K	0MS	C++	530B
Code：
/*随机化*/	
#include<cstdio>
#include<cstdlib>
int n,a[10001],b[10001];
int find(int l,int r,int p)
{
    if (l==r) return a[l];
	int mid=rand()%(r-l)+l,x=a[mid],i=l-1,j=r+1;
	for (int k=l;k<=r;++k){
		if (k==mid) continue;
		if (a[k]<x) b[++i]=a[k];
		else b[--j]=a[k];
	}
	b[++i]=x;
	for (int k=l;k<=r;++k) a[k]=b[k];
	if (i==p) return x;
	if (i<p)  return find(i+1,r,p);
	if (i>p)  return find(l,i-1,p);
}
int main()
{
	scanf("%d",&n);
	for (int i=1;i<=n;++i) scanf("%d",&a[i]);
	printf("%d\n",find(1,n,(n+1)>>1));
}

11352057	nblt	2388	Accepted	244K	16MS	C++ 489B
Code1:
/*非随机化*/
#include<cstdio>
#include<cstdlib>
int n,a[10001],b[10001];
int find(int l,int r,int p)
{
	int mid=l,x=a[mid],i=l-1,j=r+1;
	for (int k=l;k<=r;++k){
		if (k==mid) continue;
		if (a[k]<x) b[++i]=a[k];
		else b[--j]=a[k];
	}
	b[++i]=x;
	for (int k=l;k<=r;++k) a[k]=b[k];
	if (i==p) return x;
	if (i<p)  return find(i+1,r,p);
	if (i>p)  return find(l,i-1,p);
}
int main()
{
	scanf("%d",&n);
	for (int i=1;i<=n;++i) scanf("%d",&a[i]);
	printf("%d\n",find(1,n,(n+1)>>1));
}
11352024	nblt	2388	Time Limit Exceeded   C++  491B
Code2:
#include<cstdio>
int n,a[10001],b[10001];
int find(int l,int r,int p)
{
	int mid=(l+r)>>1,x=a[mid],i=l-1,j=r+1;
	for (int k=l;k<=r;++k){
		if (k==mid) continue;
		if (a[k]<x) b[++i]=a[k];
		else b[--j]=a[k];
	}
	b[++i]=x;
	for (int k=l;k<=r;++k) a[k]=b[k];
	if (i-l+1==p) return x;
	if (i-l+1<p)  return find(i+1,r,p-i);
	if (i-l+1>p)  return find(l,i-1,p);
}
int main()
{
	scanf("%d",&n);
	for (int i=1;i<=n;++i) scanf("%d",&a[i]);
	printf("%d\n",find(1,n,(n+1)>>1));
}
注：此程序仅供参考