CF733D Kostya the Sculptor[贪心 排序]
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Kostya is a genial sculptor, he has an idea: to carve a marble sculpture in the shape of a sphere. Kostya has a friend Zahar who works at a career. Zahar knows about Kostya‘s idea and wants to present him a rectangular parallelepiped of marble from which he can carve the sphere.
Zahar has n stones which are rectangular parallelepipeds. The edges sizes of the i-th of them are ai, bi and ci. He can take no more than two stones and present them to Kostya.
If Zahar takes two stones, he should glue them together on one of the faces in order to get a new piece of rectangular parallelepiped of marble. Thus, it is possible to glue a pair of stones together if and only if two faces on which they are glued together match as rectangles. In such gluing it is allowed to rotate and flip the stones in any way.
Help Zahar choose such a present so that Kostya can carve a sphere of the maximum possible volume and present it to Zahar.
The first line contains the integer n (1 ≤ n ≤ 105).
n lines follow, in the i-th of which there are three integers ai, bi and ci (1 ≤ ai, bi, ci ≤ 109) — the lengths of edges of the i-th stone. Note, that two stones may have exactly the same sizes, but they still will be considered two different stones.
In the first line print k (1 ≤ k ≤ 2) the number of stones which Zahar has chosen. In the second line print k distinct integers from 1 to n — the numbers of stones which Zahar needs to choose. Consider that stones are numbered from 1 to n in the order as they are given in the input data.
You can print the stones in arbitrary order. If there are several answers print any of them.
6
5 5 5
3 2 4
1 4 1
2 1 3
3 2 4
3 3 4
1
1
7
10 7 8
5 10 3
4 2 6
5 5 5
10 2 8
4 2 1
7 7 7
2
1 5
In the first example we can connect the pairs of stones:
- 2 and 4, the size of the parallelepiped: 3 × 2 × 5, the radius of the inscribed sphere 1
- 2 and 5, the size of the parallelepiped: 3 × 2 × 8 or 6 × 2 × 4 or 3 × 4 × 4, the radius of the inscribed sphere 1, or 1, or 1.5respectively.
- 2 and 6, the size of the parallelepiped: 3 × 5 × 4, the radius of the inscribed sphere 1.5
- 4 and 5, the size of the parallelepiped: 3 × 2 × 5, the radius of the inscribed sphere 1
- 5 and 6, the size of the parallelepiped: 3 × 4 × 5, the radius of the inscribed sphere 1.5
Or take only one stone:
- 1 the size of the parallelepiped: 5 × 5 × 5, the radius of the inscribed sphere 2.5
- 2 the size of the parallelepiped: 3 × 2 × 4, the radius of the inscribed sphere 1
- 3 the size of the parallelepiped: 1 × 4 × 1, the radius of the inscribed sphere 0.5
- 4 the size of the parallelepiped: 2 × 1 × 3, the radius of the inscribed sphere 0.5
- 5 the size of the parallelepiped: 3 × 2 × 4, the radius of the inscribed sphere 1
- 6 the size of the parallelepiped: 3 × 3 × 4, the radius of the inscribed sphere 1.5
It is most profitable to take only the first stone.
题意:一堆矩形平行六面体(雾
一堆长方体,可以选一个也可以选两个粘起来,求最大的球选哪个
最近数学正好在学立体几何................
园半径是min(a,b,c)/2,让最小边最大就好了
两个粘起来,一定是把最短边粘起来了,否则没有影响啊
所以每个长方体x最长边y次长边z最短边,然后按x,y,z优先级排序,看看相邻两个能不能粘起来行了
#include <iostream> #include <cstdio> #include <algorithm> #include <cstring> #include <cmath> using namespace std; const int N=1e5+5,INF=1e9+5; inline int read(){ char c=getchar();int x=0,f=1; while(c<‘0‘||c>‘9‘){if(c==‘-‘)f=-1;c=getchar();} while(c>=‘0‘&&c<=‘9‘){x=x*10+c-‘0‘;c=getchar();} return x*f; } int n,t[4],ans1,p1,ans2,p2; struct rec{ int id,x,y,z; bool operator <(const rec &r)const{ if(x==r.x){ if(y==r.y) return z>r.z; else return y>r.y; }else return x>r.x; } }a[N]; int main(){ n=read(); for(int i=1;i<=n;i++){ t[1]=read();t[2]=read();t[3]=read(); sort(t+1,t+4); a[i].x=t[3],a[i].y=t[2],a[i].z=t[1]; a[i].id=i; if(a[i].z>ans1) ans1=a[i].z,p1=i; } sort(a+1,a+1+n); for(int i=1;i<=n;i++){ if(a[i].x==a[i+1].x&&a[i].y==a[i+1].y){ int t=min(a[i].y,a[i].z+a[i+1].z); if(t>ans2) ans2=t,p2=i; } } if(ans1>ans2) printf("1\n%d",p1); else printf("2\n%d %d",a[p2].id,a[p2+1].id); }
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