Hdu 4003 Tree-shaped dp+ Group backpack

Still a status group

---ask K robots to start at the same point and traverse the minimum cost required for all points

Sample INPUT3 1 11 2 11 3 13 1 21 2 11 3 1

Sample Output32

1 /*2 HDU 40033 tree-shaped dp+ can only select one item of the group backpack4 5 Dp[pos][num] Indicates that the minimum value of NUM robots is used under a sub-tree with POS as the root node6 In particular, when num==0, Dp[pos][0] said to use a robot to go through all the subtrees, and finally back to the POS node7 State transfer: Dp[pos][num]=min∑{dp[pos_j][num_j]+w_j},pos_j is all the sons of Pos,8 9 Ten in order to let the group backpack only choose one, first let dp[u][0] such as backpack One  A The "group backpack" pseudo-code using a one-dimensional array is as follows: - for all Groups I -  the For V=v. 0 -  - for all k belongs to Group I -  + F[v]=max{f[v],f[v-c[k]]+w[k]} -  +  A */ at  -#include <stdio.h> -#include <algorithm> -#include <string.h> -#include <iostream> - using namespacestd; in  - Const intmaxn=10010; to  + structNode - { the     intto ; *     intNext; $     intCost//the cost of the routePanax Notoginseng}edge[maxn*2];//Tree without Direction - intHEAD[MAXN]; the intTol; +  A intdp[maxn][ One];//Dp[i][j] Represents a tree with I as the root of the use of J-man. Dp[i][0] means using a person and returning to the top point . the  + voidInit () - { $memset (head,-1,sizeof(head)); $Tol=0; -Memset (DP,0,sizeof(DP)); - } the  - voidAddintAintBintval)Wuyi { theedge[tol].to=b; -edge[tol].cost=Val; Wuedge[tol].next=Head[a]; -head[a]=tol++; Aboutedge[tol].to=A; $edge[tol].cost=Val; -edge[tol].next=Head[b]; -head[b]=tol++; - } A  + intn,k; the  - voidDfsintUintpre) $ { the      for(inti=head[u];i!=-1; i=edge[i].next) the     { the         intv=edge[i].to; the         if(V==pre)Continue; - DFS (v,u); in          for(intk=k;k>=0; k--) the         { thedp[u][k]+=dp[v][0]+2*edge[i].cost;//Put dp[u][0] in your backpack and make sure you pick at least one About          //Group Backpack the              for(intj=1; j<=k;j++) theDp[u][k]=min (dp[u][k],dp[u][k-j]+dp[v][j]+j*edge[i].cost); the         } +     } - } the intMain ()Bayi { the     intS; the     intA,b,val; -      while(SCANF ("%d%d%d", &n,&s,&k)! =EOF) -     { the init (); the          for(intI=1; i<n;i++) the         { thescanf"%d%d%d",&a,&b,&val); - Add (a,b,val); the         } theDFS (s,-1); theprintf"%d\n", Dp[s][k]);94     } the     return 0; the}

Hdu 4003 Tree-shaped dp+ Group backpack