3399.cpp

这些是我到目前在PKU上做出的题目

#include <iostream.h>

int a[105],n,k,i,j,p,o,t;
bool u[105];

int main()
{
	cin>>n>>k;
	for (i=1;i<=n;i++)
		cin>>a[i];
	for (i=1;i<=n-1;i++)
		for (j=i+1;j<=n;j++)
			if (a[i]<a[j])
			{
				t=a[i];
				a[i]=a[j];
				a[j]=t;
			}
	for (i=1;i<=n;i++)
		u[i]=0;
	for (i=1;i<=k;i++)
		u[i]=1;
	p=k;o=n;
	if (a[1]>=0 || k%2==0)
		while (p>=2)
		{
			if (a[p]*a[p-1]<a[o]*a[o-1])
			{
				u[p]=0;u[p-1]=0;
				u[o]=1;u[o-1]=1;
				p=p-2;o=o-2;
			}
			else
				break;
		}
	for (i=1;i<=n;i++)
		if (u[i])
			cout<<a[i]<<"\n";
	return 0;
}