BZOJ 3681 Arietta

#include<cstdio>
#include<cstring>
#include<cmath>
#include<queue>
#include<algorithm>

#pragma GCC optimize(3)
#define maxn 400005
#define maxm 3000005
#define INF 0x3f3f3f3f

using namespace std;

inline int getint()
{
    int num=0,flag=1;char c;
    while((c=getchar())<‘0‘||c>‘9‘)if(c==‘-‘)flag=-1;
    while(c>=‘0‘&&c<=‘9‘)num=num*10+c-48,c=getchar();
    return num*flag;
}

int n,m,K,S,T;
int fir[maxn],nxt[maxm],to[maxm],cap[maxm],cnt;
int h[maxn],tp[maxn];
vector<int>G[maxn];
int H[maxn],sz[maxn];
int rt[maxn],lc[maxn],rc[maxn],cur;

inline void newnode(int u,int v,int w)
{to[++cnt]=v,nxt[cnt]=fir[u],fir[u]=cnt,cap[cnt]=w;}
inline void insert(int u,int v,int w)
{newnode(u,v,w),newnode(v,u,0);}

inline bool bfs()
{
    memset(h,-1,sizeof h);
    queue<int>Q;h[S]=0,Q.push(S);
    while(!Q.empty())
    {
        int u=Q.front();Q.pop();
        for(int i=fir[u];i;i=nxt[i])
            if(cap[i]&&!~h[to[i]])
            {
                h[to[i]]=h[u]+1,Q.push(to[i]);
                if(to[i]==T)return 1;
            }
    }
    return 0;
}

inline int aug(int u,int flow)
{
    if(u==T)return flow;
    int used=0;
    for(int i=tp[u];i;i=nxt[i])
    {
        tp[u]=i;
        if(cap[i]&&h[to[i]]==h[u]+1)
        {
            int w=flow-used;
            w=aug(to[i],min(cap[i],w));
            cap[i]-=w,cap[i^1]+=w,used+=w;
            if(used==flow)return flow;
        }
    }
    if(!used)h[u]=-1;
    return used;
}

inline int dinic()
{
    int num=0;
    while(bfs())memcpy(tp,fir,sizeof fir),num+=aug(S,INF);
    return num;
}

inline void Insert(int &now,int l,int r,int i)
{
    now=++cur;
    if(l==r){insert(T+now,i,INF);return;}
    int mid=(l+r)>>1;
    if(H[i]<=mid)Insert(lc[now],l,mid,i),insert(T+now,T+lc[now],INF);
    else Insert(rc[now],mid+1,r,i),insert(T+now,T+rc[now],INF);
}

inline void Link(int now,int l,int r,int ql,int qr,int u)
{
    if(!now)return;
    if(ql<=l&&r<=qr){insert(u,T+now,INF);return;}
    int mid=(l+r)>>1;
    if(ql<=mid)Link(lc[now],l,mid,ql,qr,u);
    if(qr>mid)Link(rc[now],mid+1,r,ql,qr,u);
}

inline int Merge(int u,int v,int l,int r)
{
    if(!u||!v)return u+v;
    int tmp=++cur;
    if(l==r)
    {
        insert(T+tmp,T+u,INF),insert(T+tmp,T+v,INF);
        return tmp;
    }
    int mid=(l+r)>>1;
    if((lc[tmp]=Merge(lc[u],lc[v],l,mid)))insert(T+tmp,T+lc[tmp],INF);
    if((rc[tmp]=Merge(rc[u],rc[v],mid+1,r)))insert(T+tmp,T+rc[tmp],INF);
    return tmp;
}

inline void dfs(int u)
{
    Insert(rt[u],1,n,u);
    for(int i=0;i<sz[u];i++)dfs(G[u][i]),rt[u]=Merge(rt[u],rt[G[u][i]],1,n);
}

int main()
{
    n=getint(),m=getint();
    for(int i=2;i<=n;i++)
    {
        int u=getint();
        G[u].push_back(i),sz[u]++;
    }
    S=n+m+1,T=S+1;cnt=1;
    for(int i=1;i<=n;i++)H[i]=getint(),insert(i,T,1);
    dfs(1);
    for(int i=1;i<=m;i++)
    {
        int l=getint(),r=getint(),u=getint(),t=getint();
        insert(S,i+n,t),Link(rt[u],1,n,l,r,i+n);
    }
    printf("%d\n",dinic());
}