A group of researchers are designing an experiment to
test the IQ of a monkey. They will hang a banana at the roof of a building, and
at the mean time, provide the monkey with some blocks. If the monkey is clever
enough, it shall be able to reach the banana by placing one block on the top
another to build a tower and climb up to get its favorite food.
The
researchers have n types of blocks, and an unlimited supply of blocks of each
type. Each type-i block was a rectangular solid with linear dimensions (xi, yi,
zi). A block could be reoriented so that any two of its three dimensions
determined the dimensions of the base and the other dimension was the height.
They want to make sure that the tallest tower possible by stacking
blocks can reach the roof. The problem is that, in building a tower, one block
could only be placed on top of another block as long as the two base dimensions
of the upper block were both strictly smaller than the corresponding base
dimensions of the lower block because there has to be some space for the monkey
to step on. This meant, for example, that blocks oriented to have equal-sized
bases couldn‘t be stacked.
Your job is to write a program that
determines the height of the tallest tower the monkey can build with a given set
of blocks.
The input file will contain one or more test cases. The
first line of each test case contains an integer n,
representing the number
of different blocks in the following data set. The maximum value for n is
30.
Each of the next n lines contains three integers representing the values
xi, yi and zi.
Input is terminated by a value of zero (0) for n.
For each test case, print one line containing the case
number (they are numbered sequentially starting from 1) and the height of the
tallest possible tower in the format "Case case: maximum height =
height".
1
10 20 30
2
6 8 10
5 5 5
7
1 1 1
2 2 2
3 3 3
4 4 4
5 5 5
6 6 6
7 7 7
5
31 41 59
26 53 58
97 93 23
84 62 64
33 83 27
0
Case 1: maximum height = 40
Case 2: maximum height = 21
Case 3: maximum height = 28
Case 4: maximum height = 342
大意是求DAG模型的最大高度，每个盒子有无限个，所以对盒子来说有三种可能的高度（长宽倒置不考虑）；
代码：
#include<bits/stdc++.h>
using namespace std;
int dp[10005];
struct C
{
int x,y;
int height;
};
bool cmp(C a,C b)
{
return a.y<=b.y;
}
bool operator<(C a,C b)
{
if (a.x<b.x&&a.y<b.y) return 1;
else if (a.x<b.y&&a.y<b.x) return 1;
else return 0;
}
int main()
{
C B[10005];
int a,b,c,i,j,maxn,n,k=0;
while (cin>>n&&n){int p=-1;maxn=-1;k++;
memset(dp,0,sizeof(dp));
for (i=1;i<=n;i++){
scanf("%d%d%d",&a,&b,&c);
B[++p].x=min(a,b),B[p].y=max(a,b),B[p].height=c;
B[++p].x=min(b,c),B[p].y=max(b,c),B[p].height=a;
B[++p].x=min(a,c),B[p].y=max(a,c),B[p].height=b;
}
sort(B,B+p+1,cmp);
for (i=0;i<=p;i++){int sumn=0;
for (j=0;j<i;j++)
{
if (B[j]<B[i]&&dp[j]>sumn) sumn=dp[j];
}
dp[i]=sumn+B[i].height;
maxn=max(maxn,dp[i]);
}
printf("Case %d: maximum height = %d\n",k,maxn);
}
return 0;
}
基本就是N^2做法没啥好说的，排序把我坑了，应该只按照一条边来排序或者按S排序就ac，
由于我是按两条边排的wa几次>_<
