hdu3966 树链剖分+成段更新

#pragma comment(linker, "/STACK:1024000000,1024000000")
#include<queue>
#include<stack>
#include<cmath>
#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#define INF 99999999
#define ll __int64
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
using namespace std;
const int MAXN = 50010;
struct node
{
int to;
int v;
int next;
}edge[MAXN*3];
int pre[MAXN],ind,top[MAXN],fa[MAXN],son[MAXN],w[MAXN],deq[MAXN],siz[MAXN],fn;
int tree[MAXN<<2],mark[MAXN<<2];
int n,m,val[MAXN];
void add(int x,int y)
{
edge[ind].to = y;
edge[ind].next = pre[x];
pre[x] = ind++;
}
void dfs1(int rt,int pa,int d)
{
deq[rt] = d;
son[rt] = 0;
fa[rt] = pa;
siz[rt] = 1;
int i;
for(i=pre[rt]; i!=-1; i=edge[i].next){
int t = edge[i].to;
if(t != fa[rt]){
dfs1(t,rt,d+1);
siz[rt] += siz[t];
if(siz[son[rt]] < siz[t]){
son[rt] = t;
}
}
}
}
void dfs2(int rt,int tp)
{
w[rt] = ++fn;
top[rt] = tp;
if(son[rt] != 0)
dfs2(son[rt], tp);
for(int i=pre[rt]; i!=-1; i=edge[i].next){
int t = edge[i].to;
if(t != son[rt] && t != fa[rt]){
dfs2(t,t);
}
}
}
void build(int l,int r,int rt)
{
tree[rt] = 0;
mark[rt] = 0;
if(l == r)
return ;
int m = (l+r)/2;
build(lson);
build(rson);
}
void pushdown(int rt)
{
if(mark[rt] != 0){
mark[rt<<1|1] += mark[rt];
mark[rt<<1] += mark[rt];
tree[rt<<1|1] += mark[rt];
tree[rt<<1] += mark[rt];
mark[rt] = 0;
}
}
void Insert(int p,int v,int l,int r,int rt)
{
if(l == r){
tree[rt] = v;
return ;
}
int m = (l+r)/2;
if(m >= p){
Insert(p,v,lson);
}
else Insert(p,v,rson);
}
void updata(int L,int R,int v,int l,int r,int rt)
{
if(L<=l && r<=R){
mark[rt] += v;
tree[rt] += v;
return ;
}
pushdown(rt);

int m = (l+r)/2;
if(m >= L){
updata(L,R,v,lson);
}
if(m < R){
updata(L,R,v,rson);
}
}
int query(int p,int l,int r,int rt)
{
if(l == r){
return tree[rt];
}
pushdown(rt);
int m = (l+r)/2;
if(m >= p){
return query(p,lson);
}
else {
return query(p,rson);
}
}
void updata_all(int x,int y,int z)
{
while(top[x] != top[y])
{
if(deq[top[x]] < deq[top[y]]){
swap(x,y);
}
updata(w[top[x]],w[x],z,1,fn,1);

x = fa[top[x]];
}
if(deq[x] < deq[y]){
swap(x,y);
}
updata(w[y],w[x],z,1,fn,1);
}
int main()
{
int i,j,p;
while(~scanf("%d%d%d",&n,&m,&p))
{
for(i=1; i<=n; i++){
scanf("%d",&val[i]);
}
ind = 1;
memset(pre,-1,sizeof(pre));
for(i=1; i<=m; i++){
int x,y;
scanf("%d%d",&x,&y);
add(x,y);
add(y,x);
}
dfs1(1,1,1);
fn = 0;
dfs2(1,1);

build(1,n,1);
for(i=1; i<=n; i++){
Insert(w[i],val[i],1,fn,1);
}
char s[10];
while(p--)
{
scanf("%s",s);
if(s[0] == 'I'){
int x,y,z;
scanf("%d%d%d",&x,&y,&z);
updata_all(x,y,z);
}
else if(s[0] == 'D'){
int x,y,z;
scanf("%d%d%d",&x,&y,&z);
updata_all(x,y,-z);
}
else {
int x;
scanf("%d",&x);
printf("%d\n",query(w[x],1,fn,1));
}
}
}
}