hdu 5834 四面体 观察+暴力
Magic boy Bi Luo with his excited tree
Time Limit: 8000/4000 MS (Java/Others) Memory Limit: 131072/131072 K (Java/Others)
Total Submission(s): 767 Accepted Submission(s): 201
Problem Description
Bi Luo is a magic boy, he also has a migic tree, the tree has N nodes , in each node , there is a treasure, it's value is V[i], and for each edge, there is a cost C[i], which means every time you pass the edge i , you need to pay C[i].
You may attention that every V[i] can be taken only once, but for some C[i] , you may cost severial times.
Now, Bi Luo define ans[i] as the most value can Bi Luo gets if Bi Luo starts at node i.
Bi Luo is also an excited boy, now he wants to know every ans[i], can you help him?
You may attention that every V[i] can be taken only once, but for some C[i] , you may cost severial times.
Now, Bi Luo define ans[i] as the most value can Bi Luo gets if Bi Luo starts at node i.
Bi Luo is also an excited boy, now he wants to know every ans[i], can you help him?
Input
First line is a positive integer T(T≤104) , represents there are T test cases.
Four each test:
The first line contain an integer N(N≤105).
The next line contains N integers V[i], which means the treasure’s value of node i(1≤V[i]≤104).
For the next N−1 lines, each contains three integers u,v,c , which means node u and node v are connected by an edge, it's cost is c(1≤c≤104).
You can assume that the sum of N will not exceed 106.
Four each test:
The first line contain an integer N(N≤105).
The next line contains N integers V[i], which means the treasure’s value of node i(1≤V[i]≤104).
For the next N−1 lines, each contains three integers u,v,c , which means node u and node v are connected by an edge, it's cost is c(1≤c≤104).
You can assume that the sum of N will not exceed 106.
Output
For the i-th test case , first output Case #i: in a single line , then output N lines , for the i-th line , output ans[i] in a single line.
Sample Input
1
5
4 1 7 7 7
1 2 6
1 3 1
2 4 8
3 5 2
Sample Output
Case #1:
15
10
14
9
15
Author
UESTC
Source
#include <iostream>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <vector>
#include <queue>
#include <map>
#include <algorithm>
#include <set>
#define MM(a,b) memset(a,b,sizeof(a))
typedef long long ll;
typedef unsigned long long ULL;
const double eps = 1e-8;
const int inf = 0x3f3f3f3f;
const double pi=acos(-1);
using namespace std;
const int N=1e5+8;
struct Point{
ll x,y,z,dis;
int id;
void read(){
scanf("%lld%lld%lld",&x,&y,&z);
}
bool operator<(const Point &a) const{
return this->dis<a.dis;
}
}p[205],v[205];
Point operator-(Point a,Point b)
{
return (Point){a.x-b.x,a.y-b.y,a.z-b.z};
}
double dis(Point a)
{
return a.x*a.x+a.y*a.y+a.z*a.z;
}
Point cross(Point a,Point b)
{
return (Point){a.y*b.z-a.z*b.y,a.z*b.x-a.x*b.z,a.x*b.y-a.y*b.x};
}
double area(Point a,Point b,Point c)
{
return dis(cross(b-a,c-a));
}
double dot(Point a,Point b)
{
return a.x*b.x+a.y*b.y+a.z*b.z;
}
bool onface(Point a,Point b,Point c,Point d)
{
Point f=cross(a-b,c-b);
return dot(f,d-b)==0;
}
int main()
{
int cas,n,kk=0,x,y;
scanf("%d",&cas);
while(cas--)
{
scanf("%d",&n);
for(int i=1;i<=n;i++) p[i].read();
ll ans6=0,ans45=0;
for(int i=1;i<=n;i++)
for(int j=i+1;j<=n;j++)
{
ll len=dis(p[i]-p[j]);
int cnt=0;
for(int k=1;k<=n;k++)
if(k!=i&&k!=j)
{
if(dis(p[k]-p[i])-dis(p[k]-p[j])==0)
{
v[++cnt]=p[k];
v[cnt].dis=dis(p[k]-p[i]);
}
}
for(int k=1;k<=cnt;k++)
for(int w=k+1;w<=cnt;w++)
{
if((v[w].dis-v[k].dis)!=0) continue;
if(onface(p[i],p[j],v[k],v[w])) continue;
ll tmp=dis(v[w]-v[k]);
if((tmp-len)==0&&(len-v[k].dis)==0) ans6++;
else ans45++;
}
}
ans45/=2;ans6/=6;
printf("Case #%d: %lld\n",++kk,ans45+ans6);
}
return 0;
}
分析:只想说两点:
1.两点连线的中垂线经过的整格点肯定是不多的,所以由此可以暴力。
2.T了话尝试去掉sqrt
你说,我们都会幸福的,对吧?

浙公网安备 33010602011771号