BZOJ 4712: 洪水 挖坑待补

Code:

#include<bits/stdc++.h>
#define setIO(s) freopen(s".in","r",stdin)
#define maxn 200001
#define inf 1000000000
#define lson (now<<1)
#define rson ((now<<1)|1)
using namespace std;
char ask[10];
int hd[maxn],to[maxn<<1],nex[maxn<<1],V[maxn],DP[maxn];
int siz[maxn],hson[maxn],top[maxn],ln[maxn],dfn[maxn],fa[maxn],bot[maxn];
int edges,n,Q,tim;
void add(int u,int v)
{
	nex[++edges] = hd[u], hd[u] = edges,to[edges] = v;
}
void dfs1(int u,int ff)
{
	siz[u]=1,fa[u]=ff;
	for(int i=hd[u];i;i=nex[i])
	{
	    int v=to[i];
	    if(v==ff) continue;
	    dfs1(v,u);
	    siz[u]+=siz[v];
	    if(siz[v]>siz[hson[u]]) hson[u]=v;
	}
}
void dfs2(int u,int tp)
{
	ln[++tim]=u,dfn[u]=tim,top[u]=tp;
	if(hson[u])
		dfs2(hson[u],tp),bot[u]=bot[hson[u]];
	else
		bot[u]=u;
	for(int i=hd[u];i;i=nex[i])
	{
		int v=to[i];
		if(v==fa[u]||v==hson[u]) continue;
		dfs2(v,v);
	}
}
void dfs(int u)
{
	int sum=0;
	for(int i=hd[u];i;i=nex[i])
	{
		int v=to[i];
		if(v==fa[u]||v==hson[u]) continue;
		dfs(v);
		sum+=DP[v];
	}
	DP[u]=min(V[u],sum);
}

int sumv[maxn],lmin[maxn],val[maxn];
void pushup(int now)
{
	sumv[now]=sumv[lson]+sumv[rson];
	lmin[now]=min(lmin[lson],sumv[lson]+lmin0[rson]);
}
void build(int l,int r,int now)
{
	if(l>r) return;
	if(l==r)
	{
		int u=ln[l],sum=0;
		for(int i=hd[u];i;i=nex[i])
		{
			int v=to[i];
			if(v==fa[u]||v==hson[u]) continue;
			sum+=DP[v];
		}
		if(sum==0)
			val[u]=V[u];
		else
			val[u]=min(V[u],sum);
		pushup(now);
		return;
	}
	int mid=(l+r)>>1;
	build(l,mid,lson);
	build(mid+1,r,rson);
	pushup(now);
}
int query(int l,int r,int now,int L,int R)
{
	if(l>=L&&r<=R)
}

int main()
{
	setIO("input");
	scanf("%d",&n);
	for(int i=1;i<=n;++i) scanf("%d",&V[i]);
	for(int i=1,u,v;i<n;++i)
	{
		scanf("%d%d",&u,&v),add(u,v),add(v,u);
	}

	dfs1(1,0),dfs2(1,1),dfs(1),DP[0]=inf, build(1,n,1);  

	scanf("%d",&Q);
	while(Q--)
	{
		scanf("%s",ask);
		if(ask[0]=='C')
		{

		}
		if(ask[0]=='Q')
		{

		}
	}
	return 0;
}