skill 分类： noip 2015-04-16 09:37 30人阅读 评论(0) 收藏

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Problem：http://pan.baidu.com/s/1dDD5Xsd

solution : 轮廓线DP

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#include<map>
#include<queue>
#include<stack>
#include<utility>
#include<string>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<ctime>
#include<cmath>
#include<iostream>
#include<algorithm>
#define Mp(x,y) std::make_pair(x,y)

const int MAXN = 55, MAXM = 505 , INF = 2e8;
const long long LINF = 1e14;

int n , m, t[MAXN][MAXN];

long long sum[MAXN][MAXN];
long long f[MAXN][MAXN][MAXM];
long long ans = 0;

int main()
{
#ifndef ONLINE_JUDGE
    freopen("skill.in","r",stdin);
    freopen("skill.out","w",stdout);
#endif

    std::cin >> n >> m;

    for(int i = 1; i <= n; i++)
       for(int j = 1; j <= n - i + 1 ; j++)
        {
         scanf("%d",&t[i][j]);
         sum[i][j] = sum[i-1][j] + t[i][j];
        }

    memset(f,-1,sizeof(f));
    f[0][1][0] = 0;
    for(int j = 1; j <= n + 1; j++)
    {
        for(int i = 0,k = 0; k <= m; k++)
        {
          f[i][j][k] = std::max(f[i][j][k],f[i][j-1][k]);
          f[i][j][k] = std::max(f[i][j][k],f[i+1][j-1][k]);
        }
        for(int i = 1; i <= n + 1 - j; i++)
          for(int k = 0; k <= m; k++)
        {
            if(k-1 >= 0 && f[i-1][j][k-1] != -1)
               f[i][j][k] = t[i][j] + f[i-1][j][k-1];
            if(k-i >= 0 && f[i+1][j-1][k-i] != -1)
            {
                long long tmp = f[i+1][j-1][k-i] + sum[i][j];
                f[i][j][k] = std::max(f[i][j][k],tmp);
            }
        }
    }
    for(int i = 0,j = 1; j <= n + 1; j++)
       for(int k = 0; k <= m; k++)
         ans = std::max(ans,f[i][j][k]);

    std::cout << ans << std::endl;

    fprintf(stderr,"%f",clock()*1.0/CLOCKS_PER_SEC);
#ifndef ONLINE_JUDGE
    fclose(stdin);
    fclose(stdout);
#endif
    return 0;
}

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