P2515 [HAOI2010]软件安装

树形背包

  1 #include<cstdio>
  2 #include<cstdlib>
  3 #include<algorithm>
  4 #include<cstring>
  5 #include<vector>
  6 #define MAXN 110
  7 #define MAXM 510
  8 #define pii pair<int,int>
  9 #define rint register int
 10 #define mp make_pair
 11 #define pb push_back
 12 using namespace std;
 13 int read(){
 14     int x=0,f=1;char ch=getchar();
 15     while(ch<'0'||ch>'9'){if('-'==ch)f=-1;ch=getchar();}
 16     while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
 17     return x*f;    
 18 }
 19 int tot,m;
 20 int C[MAXN],V[MAXN];
 21 vector<int> G[MAXN];
 22 int dfn[MAXN],low[MAXN],sta[MAXN],b[MAXN],top,idx;
 23 int c[MAXN],v[MAXN],cmp[MAXN],n;
 24 int fst[MAXN],nxt[MAXN],from[MAXN],to[MAXN],cnt,pin[MAXN];
 25 void add(int x,int y){
 26     nxt[++cnt]=fst[x],fst[x]=cnt,from[cnt]=x,to[cnt]=y;    
 27     pin[y]++;
 28 }
 29 void tarjan(int x){
 30     dfn[x]=low[x]=(++idx);
 31     sta[++top]=x,b[x]=1;
 32     int y;
 33     for(rint i=0;i<G[x].size();i++){
 34         y=G[x][i];
 35         if(!dfn[y]){
 36             tarjan(y);    
 37             low[x]=min(low[x],low[y]);
 38         }
 39         else if(b[y]){
 40             low[x]=min(low[x],dfn[y]);
 41         }
 42     }
 43     if(dfn[x]==low[x]){
 44         n++;
 45         while(sta[top+1]!=x){
 46             c[n]+=C[sta[top]];
 47             v[n]+=V[sta[top]];
 48             cmp[sta[top]]=n;
 49             b[sta[top]]=0;
 50             top--;    
 51         }
 52     }
 53 }
 54 int f[MAXN][MAXM],dep[MAXN];
 55 int H[MAXM],H1[MAXM],H2[MAXM];
 56 void work(int x,int vl){
 57     if(vl<c[x]){f[x][vl]=0;return;}
 58     vl-=c[x];
 59     memset(H,0,sizeof(H));
 60     memset(H1,0,sizeof(H1));
 61     int y,r=0;
 62     for(rint e=fst[x];e;e=nxt[e]){
 63         y=to[e];
 64         for(rint i=0;i<=vl;i++){
 65             H[i]=max(H[i],H1[i]+f[y][vl-i]);
 66             r=max(r,H[i]);
 67         }
 68         memcpy(H1,H,sizeof(H));
 69     }
 70     f[x][vl+c[x]]=r+v[x];
 71 }
 72 void dp(int x){
 73     b[x]=1;
 74     int y;
 75     for(rint e=fst[x];e;e=nxt[e]){
 76         y=to[e];
 77         if(!b[y]){
 78             dp(y);
 79             for(rint j=m-c[x];j>=0;j--){
 80                 for(rint k=0;k<=j;k++){
 81                     f[x][j]=max(f[x][j],f[x][k]+f[y][j-k]);
 82                 }
 83             }
 84         }
 85     }
 86     for(rint j=m;j>=0;j--){
 87         if(j>=c[x]){
 88             f[x][j]=f[x][j-c[x]]+v[x];
 89         }
 90         else{
 91             f[x][j]=0;
 92         }
 93     }
 94 }
 95 int main()
 96 {
 97   //  freopen("data.in","r",stdin);
 98     tot=read();m=read();
 99     for(rint i=1;i<=tot;i++)C[i]=read();
100     for(rint i=1;i<=tot;i++)V[i]=read();
101     int tmp;
102     for(rint i=1;i<=tot;i++){
103         tmp=read();
104         if(tmp)G[tmp].pb(i);
105     }
106     for(rint i=1;i<=tot;i++){
107         if(!dfn[i])tarjan(i);    
108     }
109     for(rint i=1;i<=tot;i++){
110         for(rint j=0;j<G[i].size();j++){
111             int x=i,y=G[i][j];
112             if(cmp[x]!=cmp[y]){
113                 add(cmp[x],cmp[y]);
114             }
115         }
116     }
117     for(rint i=1;i<=n;i++){
118         if(!pin[i]){
119             add(0,i);    
120         }
121     }
122 //    for(rint i=1;i<=cnt;i++){
123 //        printf("%d %d\n",from[i],to[i]);    
124 //    }
125     memset(b,0,sizeof(b));
126     dp(0);
127     printf("%d\n",f[0][m]);
128     return 0;    
129 }

 

posted @ 2018-03-12 20:06  white_hat_hacker  阅读(171)  评论(0)  编辑  收藏  举报