ecnu 1244

顺序可略，多阶段决策，1.当前木块放在第col上面，2.当前木块另起col，3.舍弃

#include <iostream>
#include <cstring>
using namespace std;

struct Block{
    int lens[3];
};

Block blocks[110];
int DP[110][110][110][3];

int M, N;


int judge( int bellow, int f1, int up, int f2 ){

    int bellow_a = blocks[bellow].lens[f1];
    int bellow_b = blocks[bellow].lens[( f1 + 1 ) % 3];
    int up_a     = blocks[up].lens[f2];
    int up_b     = blocks[up].lens[( f2 + 1 ) % 3];

    if( ( up_a <= bellow_a && up_b <= bellow_b ) ||
        ( up_a <= bellow_b && up_b <= bellow_a ) )
        return blocks[up].lens[( f2 + 2 ) % 3];

    return 0;
}


int res_search( int col , int used, int top, int face ){

    if( DP[col][used][top][face] )
        return DP[col][used][top][face];

    if( col == M && used == N )
        return 0;

    if( col != M && used == N )
        return -1;

    int res = 0;

    if( col ){
        for( int f = 0; f <= 2; ++f ){

            int ok = judge( top, face, used + 1, f );

            if( ok )
                res = max( res, res_search( col, used + 1, used + 1, f ) + ok );

        }
    }

    if( col < M ){
        for( int f = 0; f <= 2; ++f ){
            res = max( res, res_search( col + 1, used + 1, used + 1, f ) + blocks[used + 1].lens[( f + 2 ) % 3] );
        }
    }

    res = max( res, res_search( col, used + 1, top, face ) );
    DP[col][used][top][face] = res;

    return res;

}


int main(){

    while( cin >> N >> M ){

        for( int i = 1; i <= N; ++i ){
            cin >> blocks[i].lens[0] >> blocks[i].lens[1] >> blocks[i].lens[2];
        }

        memset( DP, 0, sizeof( DP ) );

        int res = res_search( 0, 0, 0, 0 );

        cout << res << endl;
    }

    return 0;
}

ecnu 1244

原文：http://blog.csdn.net/pandora_madara/article/details/40193565