[POJ 3345] Bribing FIPA

[题目链接]

          http://poj.org/problem?id=3345

[算法]

        树形背包

[代码]

         

#include <algorithm>  
#include <bitset>  
#include <cctype>  
#include <cerrno>  
#include <clocale>  
#include <cmath>  
#include <complex>  
#include <cstdio>  
#include <cstdlib>  
#include <cstring>  
#include <ctime>  
#include <deque>  
#include <exception>  
#include <fstream>  
#include <functional>  
#include <limits>  
#include <list>  
#include <map>  
#include <iomanip>  
#include <ios>  
#include <iosfwd>  
#include <iostream>  
#include <istream>  
#include <ostream>  
#include <queue>  
#include <set>  
#include <sstream>  
#include <stdexcept>  
#include <streambuf>  
#include <string>  
#include <utility>  
#include <vector>  
#include <cwchar>  
#include <cwctype>  
#include <stack>  
#include <limits.h> 
using namespace std;
#define MAXN 210
const int INF = 2e9;

int i,j,k,root,n,m,tot,u,v,x,ans;
int size[MAXN],fa[MAXN],val[MAXN];
int f[MAXN][MAXN];
char s[MAXN];
map< string,int > mp;
vector< int > e[MAXN];

inline void dp(int u)
{
        int i,j,k,v;
        f[u][0] = 0;
        size[u] = 1;
        for (i = 0; i < (int)e[u].size(); i++)
        {
                v = e[u][i];
                dp(v);
                size[u] += size[v];
                for (j = size[u]; j >= 0; j--)
                {
                        for (k = 0; k <= size[v]; k++)
                        {
                                f[u][j] = min(f[u][j],f[u][j - k] + f[v][k]);
                        }
                }
        }
        if (u != root) f[u][size[u]] = min(f[u][size[u]],val[u]);
}

int main() 
{
        
        while (scanf("%s",&s) != EOF && strcmp(s,"#") != 0)
        {
                scanf("%d",&m);
                n = 0;
                for (i = 0; s[i] != ''; i++) n = n * 10 + s[i] - '0';
                tot = 0;
                mp.clear();
                memset(val,0,sizeof(val));
                memset(fa,0,sizeof(fa));    
                for (i = 0; i <= n; i++) e[i].clear();
                for (i = 1; i <= n; i++)
                {
                        scanf("%s%d",&s,&x);
                        if (!mp[s]) mp[s] = ++tot;
                        u = mp[s];
                        val[u] = x;
                        while (getchar() != '
')
                        {
                                scanf("%s",&s);
                                if (!mp[s]) mp[s] = ++tot;
                                v = mp[s];
                                e[u].push_back(v);
                                fa[v] = u;
                        }
                }        
                root = 0;
                for (i = 1; i <= n; i++)
                {
                        if (!fa[i])
                                e[root].push_back(i);
                }
                memset(size,0,sizeof(size));
                memset(f,0x3f,sizeof(f));
                dp(root);
                ans = INF;
                for (i = m; i <= n; i++) ans = min(ans,f[0][i]);
                printf("%d
",ans);
        }
        
        return 0;
    
}