Division into Teams CodeForces - 149C

原题链接
思路:
  结论题,排序奇偶分组,均分,没想出怎么证明

Code

#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
const int N = 100010;
int n,sum,maxn;
bool vis[N];
struct Node{
	int val,id;
	bool operator<(const Node& r){
		return this->val<r.val;
	}
}node[N];
int main()
{
	scanf("%d",&n);
	for(int i=1;i<=n;i++)
	{
		scanf("%d",&node[i].val);
		node[i].id = i;
	}//体积为n/2,价值v>=(sum-maxn)/2 
	sort(node+1,node+n+1);
	printf("%d\n",n+1>>1); 
	for(int i=1;i<=n;i++)
		if(i&1) printf("%d ",node[i].id);
	printf("\n%d\n",n-(n+1)/2);
	for(int i=1;i<=n;i++)
	    if(!(i&1)) printf("%d ",node[i].id);
	return 0;
}