【dp】例题9-2 UVa 437 (HDU 1069)

/*
基础dp
UVa 437 The Tower of Babylon
C - Monkey and Banana
时间: 2017/02/20
题意:叠放立方体,使其叠的高度最大。在按底的长宽排序后,进行求最大子序列和
题解:
1. 在按底的长宽排序后,进行求最大子序列和
2. 类似嵌套问题,记忆化搜索
*/
#include
#include
#include
#include
#include
#include
#include
using namespace std;
#define N 210
#define INF 0x3f3f3f3f
//1 ------------------------------
struct code
{
    int x,y,z;
}f[200];
bool cmp(code a,code b)
{
    if(a.x != b.x)
        return a.x > b.x;
    return a.y > b.y;
}

int main()
{
    int n;
    int k = 0;
    while(~scanf("%d",&n)&&n)
    {
        k++;
        int n1 = n;
        int i = 0;
        while(n1--)
        {
            int a[3];
            scanf("%d%d%d",&a[0],&a[1],&a[2]);
            sort(a,a+3);
            f[i].y = f[i+1].z = f[i+2].x = a[1];
            f[i].x = f[i+1].x = f[i+2].z = a[2];
            f[i].z = f[i+1].y = f[i+2].y = a[0];
            i += 3;
        }
        sort(f,f+3*n,cmp);
        int dp[200];
        int maxn=0;
        for(i=0;i<3*n;i++)
        {
            dp[i] = f[i].z;
            for(int j = i-1; j >=0; j--)
            {
                if(f[j].x > f[i].x && f[j].y > f[i].y)
                {
                    if(dp[i] < dp[j] + f[i].z)
                        dp[i] = dp[j] + f[i].z;
                }
            }
            if(dp[i] > maxn)
                maxn = dp[i];
        }
        printf("Case %d: maximum height = %d\n",k,maxn);
    }
    return 0;
}
//2 ------------------------------
struct code
{
    int x,y,z;
}f[N];
int mp[N][N],dp[N];
int n;
int dfs(int i)
{
    int &ans = dp[i];
    if(ans > 0) return ans;
    ans = f[i].z;
    for(int j = 0; j < 3*n; j++)
    {
        if(mp[i][j])
            ans = max(ans, dfs(j)+f[i].z);
    }
    return ans;
}
int main()
{
    int k = 0;
    while(~scanf("%d",&n)&&n)
    {
        k++;
        int n1 = n;
        int i = 0;
        while(n1--)
        {
            int a[3];
            scanf("%d%d%d",&a[0],&a[1],&a[2]);
            sort(a,a+3);
            f[i].y = f[i+1].z = f[i+2].x = a[1];
            f[i].x = f[i+1].x = f[i+2].z = a[2];
            f[i].z = f[i+1].y = f[i+2].y = a[0];
            i += 3;
        }
        memset(mp,0,sizeof(mp));
        memset(dp,0,sizeof(dp));
        for(int i = 0; i < 3*n; i++)
        {
            for(int j = 0; j < 3*n; j++)
            {
                if(f[i].x < f[j].x && f[i].y < f[j].y)
                    mp[i][j] = 1;
            }
        }
        int maxn = 0;
        for(int i = 0; i < 3*n; i++)
        {
            maxn = max(maxn,dfs(i));
        }
        printf("Case %d: maximum height = %d\n",k,maxn);
    }
    return 0;
}


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