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  • bzoj 4080: [Wf2014]Sensor Network【瞎搞+随机化】

    参考:https://blog.csdn.net/YihAN_Z/article/details/73380387
    一点都不想写正解.jpg
    random_shuffle一下然后贪心的加点,和ans取max即可。biutset非常方便
    正解好像是最大团还是二分图最大独立集来着?

    #include<iostream>
    #include<cstdio>
    #include<bitset>
    #include<algorithm>
    using namespace std;
    const int N=105;
    int n,d,q[N];
    bitset<N>a[N],now,ans,v,b;
    struct qwe
    {
    	int x,y;
    	bool operator < (const qwe& a) const
    	{
    		return x<a.x;
    	}
    	int operator | (const qwe& a) const
    	{
    		return (x-a.x)*(x-a.x)+(y-a.y)*(y-a.y);
    	}
    }p[N];
    int main()
    {
    	scanf("%d%d",&n,&d);
    	for(int i=1;i<=n;i++) 
    	{
    		scanf("%d%d",&p[i].x,&p[i].y);
    		q[i]=i,v[i]=1;
    	}
    	for(int i=1;i<=n;i++)
    		for(int j=i+1;j<=n;j++)
    			if((p[i]|p[j])<=d*d)
    				a[i][j]=a[j][i]=1;
    	for(int i=1;i<=1000;i++,random_shuffle(q+1,q+n+1))
    	{
    		b=v;
    		now.reset();
    		for(int j=1;j<=n;j++)
    			if(b[q[j]])
    				now[q[j]]=1,b&=a[q[j]];
    		if(now.count()>ans.count()) 
    			ans=now;
    	}
    	printf("%d
    ",ans.count());
    	for(int i=1;i<=n;i++)
    		if(ans[i]) 
    			printf("%d ",i);
    	return 0;
    }
    
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  • 原文地址:https://www.cnblogs.com/lokiii/p/8927707.html
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