hdu 5934 Bomb

Bomb

Problem Description
There are N bombs needing exploding.

Each bomb has three attributes: exploding radius ri, position (xi,yi) and lighting-cost ci which means you need to pay ci cost making it explode.

If a un-lighting bomb is in or on the border the exploding area of another exploding one, the un-lighting bomb also will explode.

Now you know the attributes of all bombs, please use the minimum cost to explode all bombs.
 
Input
First line contains an integer T, which indicates the number of test cases.

Every test case begins with an integers N, which indicates the numbers of bombs.

In the following N lines, the ith line contains four intergers xiyiri and ci, indicating the coordinate of ith bomb is (xi,yi), exploding radius is ri and lighting-cost is ci.

Limits
1T20
1N1000
108xi,yi,ri108
1ci104
 
Output
For every test case, you should output 'Case #x: y', where x indicates the case number and counts from 1 and y is the minimum cost.
 
Sample Input
1
5
0 0 1 5
1 1 1 6
0 1 1 7
3 0 2 10
5 0 1 4
 
Sample Output
Case #1: 15
 
#include<cstdio>
#include<cstring>
#include<stack>
#include<cmath>
#include<vector>
#include<algorithm>
#define pb push_back
using namespace std;
typedef long long LL;
struct Bomb
{
    LL x,y,r;
    int c;
}b[1005];
vector<int>G[1005];
int minc[1005],in[1005],pre[1005],lowlink[1005],sccno[1005],dfs_clock,scc_cnt,n;
stack<int>S;
bool jud(Bomb a,Bomb b)
{
    return sqrt((a.x-b.x)*(a.x-b.x)*1.0+(a.y-b.y)*(a.y-b.y)*1.0)<=a.r*1.0;
}
void dfs(int u)
{
    pre[u]=lowlink[u]=++dfs_clock;
    S.push(u);
    for(int i=0;i<G[u].size();i++)
    {
        int v=G[u][i];
        if(!pre[v])
        {
            dfs(v);
            lowlink[u]=min(lowlink[u],lowlink[v]);
        }
        else if(!sccno[v])
            lowlink[u]=min(lowlink[u],pre[v]);
    }
    if(lowlink[u]==pre[u])
    {
        scc_cnt++;
        while(1)
        {
            int x=S.top();
            S.pop();
            sccno[x]=scc_cnt;
            minc[scc_cnt]=min(minc[scc_cnt],b[x].c);
            if(x==u)break;
        }
    }
}
void find_scc()
{
    dfs_clock=scc_cnt=0;
    memset(sccno,0,sizeof(sccno));
    memset(pre,0,sizeof(pre));
    for(int i=0;i<=n;i++)minc[i]=1e5;
    for(int i=0;i<n;i++)if(!pre[i])dfs(i);
}
int solve()
{
    memset(in,0,sizeof(in));
    for(int i=0;i<n;i++)
        for(int j=0;j<G[i].size();j++)
            if(sccno[i]!=sccno[G[i][j]])
                in[sccno[G[i][j]]]++;
    int res=0;
    for(int i=1;i<=scc_cnt;i++)
        if(in[i]==0)res+=minc[i];
    return res;
}
int main()
{
    int T;
    scanf("%d",&T);
    for(int kase=1;kase<=T;kase++)
    {
        scanf("%d",&n);
        for(int i=0;i<n;i++)
            scanf("%lld%lld%lld%d",&b[i].x,&b[i].y,&b[i].r,&b[i].c);
        for(int i=0;i<n;i++)G[i].clear();
        for(int i=0;i<n;i++)
            for(int j=0;j<n;j++)
                if(i!=j&&jud(b[i],b[j]))
                    G[i].pb(j);
        find_scc();
        printf("Case #%d: %d\n",kase,solve());
    }
    return 0;
}

 

posted on 2016-11-02 15:34    阅读(371)  评论(0编辑  收藏  举报

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