紫书动规 例题9-2 UVA

题目链接:

https://vjudge.net/problem/UVA-437

题意:

题解:

dp[i][j]:=考虑到前i个立方体并且第i个立方体以标号为j为高的最大值

代码:

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define MS(a) memset(a,0,sizeof(a))
#define MP make_pair
#define PB push_back
const int INF = 0x3f3f3f3f;
const ll INFLL = 0x3f3f3f3f3f3f3f3fLL;
inline ll read(){
    ll x=0,f=1;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
    return x*f;
}
//////////////////////////////////////////////////////////////////////////
const int maxn = 1e5+10;

int n;
int block[40][3],d[40][3];

void get(int* v,int b,int x){
    int idx = 0;
    for(int i=0; i<3; i++)
        if(i!=x)
            v[idx++] = block[b][i];
}

int dp(int i,int j){
    if(d[i][j] >= 0) return d[i][j];
    d[i][j] = 0;
    int v[2],v2[2];
    get(v,i,j);
    for(int a=0; a<n; a++){
        for(int b=0; b<3; b++){
            get(v2,a,b);
            if(v[0]>v2[0] && v[1]>v2[1])
                d[i][j] = max(d[i][j],dp(a,b));
        }
    }
    d[i][j] += block[i][j];
    return d[i][j];
}

int main(){
    int cas = 0;
    while(scanf("%d",&n) && n){
        for(int i=0; i<n; i++){
            scanf("%d%d%d",&block[i][0],&block[i][1],&block[i][2]);
            sort(block[i],block[i]+3);
        }

        int ans = -INF;
        memset(d,-1,sizeof(d));
        for(int i=0; i<n; i++)
            for(int j=0; j<3; j++)
                ans = max(ans,dp(i,j));
        printf("Case %d: maximum height = %d
",++cas,ans);
    }

    return 0;
}