bzoj 2427

 1 #include<bits/stdc++.h>
 2 #define inc(i,l,r) for(int i=l;i<=r;i++)
 3 #define dec(i,l,r) for(int i=l;i>=r;i--)
 4 #define link(x) for(edge *j=h[x];j;j=j->next)
 5 #define mem(a) memset(a,0,sizeof(a))
 6 #define inf 1e9
 7 #define ll long long
 8 #define succ(x) (1<<x)
 9 #define NM 500+5
10 using namespace std;
11 int read(){
12     int x=0,f=1;char ch=getchar();
13     while(!isdigit(ch)){if(ch==‘-‘)f=-1;ch=getchar();}
14     while(isdigit(ch))x=x*10+ch-‘0‘,ch=getchar();
15     return x*f;
16 }
17 struct edge{
18     int t,v;
19     edge *next;
20 }e[2*NM],*h[NM],*o=e;
21 void add(int x,int y){
22     o->t=y;o->next=h[x];h[x]=o;o++;
23 }
24 int n,m,a[NM],b[NM],_d[NM][NM],d[NM],suc[NM],low[NM],_x,_y,_t,tot,cnt,ans;
25 bool v[NM];
26 stack<int >s;
27 void dfs(int x){
28     d[x]=low[x]=++tot;s.push(x);
29     link(x)
30     if(!d[j->t]){
31         dfs(j->t);
32         low[x]=min(low[x],low[j->t]);
33     }else if(!suc[j->t])
34     low[x]=min(low[x],low[j->t]);
35     if(d[x]==low[x]){
36         int t;cnt++;
37         do{
38             t=s.top();s.pop();
39             suc[t]=cnt;
40         }while(x!=t);
41     }
42 }
43 void dp(int x){
44     inc(i,a[x],m)_d[x][i]=b[x];
45     link(x){
46         dp(j->t);
47         dec(k,m,a[x])
48         inc(i,a[j->t],k-a[x])
49         if(k>=i)
50         _d[x][k]=max(_d[x][k],_d[j->t][i]+_d[x][k-i]);
51     }
52 }
53 int main(){
54 //    freopen("data.in","r",stdin);
55     n=read();m=read();
56     inc(i,1,n)a[i]=read();
57     inc(i,1,n)b[i]=read();
58     inc(i,1,n)
59     if(_x=read())
60     add(_x,i),v[i]++;
61     inc(i,1,n)
62     if(!v[i])dfs(i);
63     inc(i,1,n)
64     if(!d[i])dfs(i);
65     inc(i,1,cnt){
66         _x=_y=_t=0;
67         inc(j,1,n)
68         if(suc[j]==i)_x+=a[j],_y+=b[j],_t++;
69         if(_t==1){
70             inc(j,1,n)
71             if(suc[j]==i&&!v[j])
72             add(0,j);
73         }else{
74             a[++n]=_x;b[n]=_y;
75             add(0,n);
76             inc(k,1,n)
77             if(suc[k]==i)
78             link(k)
79             if(suc[j->t]!=i)add(n,j->t);
80         }
81     }
82     dp(0);
83     inc(i,1,m)ans=max(ans,_d[0][i]);
84     printf("%d\n",ans);
85     return 0;
86 }