HDU 5692 Snacks

#include<cstdio>
#include <iostream>
#include<cstring>
#include<cmath>
#include<vector>
#include<queue>
#include<algorithm>
using namespace std;

long long INF=10000000+10;
const int maxn=100000+10;
int n,m;
vector<int>Tree[maxn];
long long val[maxn];
int L[maxn],R[maxn],tot;
bool flag[maxn];
struct SegTree
{
long long MAX,lazy;
}s[8*maxn];
long long ans;

void dfs(int x)
{
L[x]=++tot; flag[x]=1;
for(int i=0;i<Tree[x].size();i++)
if(flag[Tree[x][i]]==0) dfs(Tree[x][i]);
R[x]=++tot;
}

void init()
{
INF=10000000+10;
INF=INF*INF;
tot=0;
memset(flag,0,sizeof flag);
for(int i=1;i<=n;i++) Tree[i].clear();
}

void build(int l,int r,int rt)
{
s[rt].MAX=s[rt].lazy=0;
if(l==r) return;
int m=(l+r)/2;
build(l,m,2*rt);
build(m+1,r,2*rt+1);
}

void pushUp(int rt)
{
s[rt].MAX=max(s[2*rt].MAX,s[2*rt+1].MAX);
}

void pushDown(int rt)
{
if(s[rt].lazy!=0)
{
s[2*rt].MAX+=s[rt].lazy;
s[2*rt+1].MAX+=s[rt].lazy;
s[2*rt].lazy+=s[rt].lazy;
s[2*rt+1].lazy+=s[rt].lazy;
s[rt].lazy=0;
}
}

void update(int L,int R,int l,int r,int rt,long long val)
{
if(L<=l&&r<=R) { s[rt].MAX+=val;s[rt].lazy+=val; return; }
int m=(l+r)/2;
pushDown(rt);
if(L<=m) update(L,R,l,m,2*rt,val);
if(R>m)  update(L,R,m+1,r,2*rt+1,val);
pushUp(rt);
}

void quary(int L,int R,int l,int r,int rt)
{
if(L<=l&&r<=R) { ans=max(ans,s[rt].MAX); return; }
int m=(l+r)/2;
pushDown(rt);
if(L<=m) quary(L,R,l,m,2*rt);
if(R>m)  quary(L,R,m+1,r,2*rt+1);
pushUp(rt);
}

int main()
{
int T; scanf("%d",&T); int Case=1;
while(T--)
{
scanf("%d%d",&n,&m);init();
for(int i=1;i<=n-1;i++)
{
int u,v; scanf("%d%d",&u,&v);
u++; v++;
Tree[u].push_back(v);
Tree[v].push_back(u);
}
for(int i=1;i<=n;i++) scanf("%lld",&val[i]);

dfs(1);
build(1,tot,1);

for(int i=1;i<=n;i++) update(L[i],R[i],1,tot,1,val[i]);

printf("Case #%d:\n",Case++);
for(int i=1;i<=m;i++)
{
int op; scanf("%d",&op);
if(op==0)
{
int x; long long y; scanf("%d%lld",&x,&y); x++;
update(L[x],R[x],1,tot,1,y-val[x]); val[x]=y;
}
else
{
int x; scanf("%d",&x); ans=-INF; x++;
quary(L[x],R[x],1,tot,1);
printf("%lld\n",ans);
}
}
}
return 0;
}