這樣的樹形態主席樹,用線段樹合併會很方便獲得每一個子樹對應的主席樹形態,注意一下細節就行了,數組大小得斟酌着開!!!..ip
可是這題內存64M仍是有點小卡的..一開始沒有判斷lson和rson是否存在就直接連邊了,形成連了大量無用的邊,MLE了一次,在連邊的時候注意一下是否有意義便可。get
不知道程序裏好像有什麼奇怪的地方..本機拍一組大樣例RE..由於連邊時有某個點編號連完後變大了10倍..其他的應該是沒什麼問題..誰知道這沙茶程序出了啥毛病(捂臉
#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<queue>
#include<vector>
using namespace std;
inline int read()
{
int x=0,f=1; char ch=getchar();
while (ch<'0' || ch>'9') {if (ch=='-') f=-1; ch=getchar();}
while (ch>='0' && ch<='9') {x=x*10+ch-'0'; ch=getchar();}
return x*f;
}
#define MAXN 400010
#define INF 0x7fffffff
int N,M,sz=1;
struct EdgeNode{
int next,to,cap;
}edge[1000010];
int head[MAXN],cnt=1;
inline void AddEdge(int u,int v,int w) {cnt++; edge[cnt].next=head[u]; head[u]=cnt; edge[cnt].to=v; edge[cnt].cap=w;}
inline void InsertEdge(int u,int v,int w) {/*printf("<%d,%d>%d\n",u,v,w);*/ AddEdge(u,v,w); AddEdge(v,u,0);}
int h[MAXN],cur[MAXN],S,T;
queue<int>q;
inline bool Bfs()
{
for (int i=0; i<=sz; i++) h[i]=-1;
q.push(S); h[S]=0;
while (!q.empty()) {
int now=q.front(); q.pop();
for (int i=head[now]; i; i=edge[i].next)
if (edge[i].cap && h[edge[i].to]==-1)
h[edge[i].to]=h[now]+1,q.push(edge[i].to);
}
return h[T]!=-1;
}
inline int Dfs(int now,int low)
{
if (now==T) return low;
int w,used=0;
for (int i=cur[now]; i; i=edge[i].next)
if (edge[i].cap && h[edge[i].to]==h[now]+1) {
int w=Dfs(edge[i].to,min(low-used,edge[i].cap));
edge[i].cap-=w; edge[i^1].cap+=w; used+=w;
if (used==low) return used;
if (edge[i].cap) cur[now]=i;
}
if (!used) h[now]=-1;
return used;
}
inline int Dinic()
{
int re=0;
while (Bfs()) {
for (int i=0; i<=sz; i++) cur[i]=head[i];
re+=Dfs(S,INF);
}
return re;
}
struct SgtNode{
int lson,rson;
}tree[10010*80];
int root[MAXN];
inline void Insert(int &x,int l,int r,int pos)
{
x=++sz;
if (l==r) {
InsertEdge(x,T,1);
return;
}
int mid=(l+r)>>1;
if (pos<=mid) Insert(tree[x].lson,l,mid,pos),InsertEdge(x,tree[x].lson,INF);
else Insert(tree[x].rson,mid+1,r,pos),InsertEdge(x,tree[x].rson,INF);
}
inline int Merge(int x,int y,int l,int r)
{
if (!x || !y) return x|y;
int z=++sz;
if (l==r) {
InsertEdge(z,x,INF),InsertEdge(z,y,INF);
return z;
}
int mid=(l+r)>>1;
tree[z].lson=Merge(tree[x].lson,tree[y].lson,l,mid);
if (tree[z].lson) InsertEdge(z,tree[z].lson,INF);
tree[z].rson=Merge(tree[x].rson,tree[y].rson,mid+1,r);
if (tree[z].rson) InsertEdge(z,tree[z].rson,INF);
return z;
}
inline void Query(int x,int l,int r,int L,int R,int id)
{
if (!x) return;
if (L<=l && R>=r) {
InsertEdge(id,x,INF);
return;
}
int mid=(l+r)>>1;
if (L<=mid) Query(tree[x].lson,l,mid,L,R,id);
if (R>mid) Query(tree[x].rson,mid+1,r,L,R,id);
}
vector<int>son[MAXN];
inline void DFS(int now)
{
for (int i=0; i<son[now].size(); i++) {
DFS(son[now][i]);
root[now]=Merge(root[now],root[son[now][i]],1,N);
}
}
int main()
{
N=read(),M=read();
for (int i=2,x; i<=N; i++) x=read(),son[x].push_back(i);
S=0,T=1;
for (int i=1,x; i<=N; i++) x=read(),Insert(root[i],1,N,x);
DFS(1);
for (int i=1; i<=M; i++) {
int L=read(),R=read(),D=read(),Ti=read();
InsertEdge(S,++sz,Ti); Query(root[D],1,N,L,R,sz);
}
printf("%d\n",Dinic());
return 0;
}