【高级数据结构】[SPOJ QTREE]树链剖分/动态树各一模板
题目:
树链剖分:
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
#define MAXN 10024
#define MAXLOG 14
#define INF 0x7fffffff
int n,T,size[MAXN+10],dep[MAXN+10],fa[MAXN+10][MAXLOG+1],wt[MAXN+10]={0,-INF},bl[MAXN+10],length[MAXN+10],id2v[MAXN+10];
int tmax[MAXN*4+10],*ttop,*root[MAXN+10],pos[MAXN+10];
bool f;
struct node{
int v,wt,pos;
node *next;
}*adj[MAXN+10],edge[MAXN*2+10],*ecnt;
void addedge(int u,int v,int wt,int pos){
node *p=++ecnt;
p->v=v;
p->wt=wt;
p->pos=pos;
p->next=adj[u];
adj[u]=p;
}
void Read(int &x){
char c;
while(c=getchar(),c!=EOF)
if(c>='0'&&c<='9'){
x=c-'0';
while(c=getchar(),c>='0'&&c<='9')
x=x*10+c-'0';
ungetc(c,stdin);
return;
}
}
void dfs1(int u,int father){
fa[u][0]=father;
dep[u]=dep[father]+1;
size[u]=1;
for(int i=1;i<=MAXLOG;i++)
fa[u][i]=fa[fa[u][i-1]][i-1];
for(node *p=adj[u];p;p=p->next){
if(p->v!=father){
id2v[p->pos]=p->v;
wt[p->v]=p->wt;
dfs1(p->v,u);
size[u]+=size[p->v];
}
}
}
inline int *NewTree(int len){
int *ret=ttop;
ttop+=len*4;
return ret;
}
void insert(int *tmax,int i,int l,int r,int pos,int wt){
if(l==r){
tmax[i]=wt;
return;
}
int mid=(l+r)>>1;
if(pos<=mid)
insert(tmax,i<<1,l,mid,pos,wt);
else
insert(tmax,(i<<1)+1,mid+1,r,pos,wt);
tmax[i]=max(tmax[i<<1],tmax[(i<<1)+1]);
}
void dfs2(int u,int len,int father){
int heavy=0,i;
for(node *p=adj[u];p;p=p->next)
if(p->v!=father&&size[p->v]>size[heavy])
heavy=p->v;
if(!heavy){
int tp=u;
for(i=1;i<len;i++)
tp=fa[tp][0];
root[tp]=NewTree(len);
length[tp]=len;
for(i=len;i;i--){
bl[u]=tp;
pos[u]=i;
insert(root[tp],1,1,len,i,wt[u]);
u=fa[u][0];
}
return;
}
dfs2(heavy,len+1,u);
for(node *p=adj[u];p;p=p->next){
if(p->v!=father&&p->v!=heavy)
dfs2(p->v,1,u);
}
}
void init(){
Read(n);
int i,u,v,wt;
for(i=1;i<n;i++){
Read(u),Read(v),Read(wt);
addedge(u,v,wt,i);
addedge(v,u,wt,i);
}
dfs1(1,0);
dfs2(1,1,0);
}
int LCA(int a,int b){
if(dep[a]<dep[b])
swap(a,b);
int i;
for(i=MAXLOG;i>=0;i--)
if(dep[a]-(1<<i)>=dep[b])
a=fa[a][i];
if(a==b)
return a;
for(i=MAXLOG;i>=0;i--)
if(fa[a][i]!=fa[b][i])
a=fa[a][i],b=fa[b][i];
return fa[a][0];
}
int find(int *tmax,int i,int l,int r,int ll,int rr){
if(l>=ll&&r<=rr)
return tmax[i];
if(l>rr||r<ll)
return -INF;
int mid=(l+r)>>1;
return max(find(tmax,i<<1,l,mid,ll,rr),find(tmax,(i<<1)+1,mid+1,r,ll,rr));
}
int query(int lca,int a){
int ret=-INF;
while(lca!=a){
if(bl[a]!=bl[lca]){
ret=max(find(root[bl[a]],1,1,length[bl[a]],1,pos[a]),ret);
a=fa[bl[a]][0];
}
else{
ret=max(find(root[bl[a]],1,1,length[bl[a]],pos[lca]+1,pos[a]),ret);
break;
}
}
return ret;
}
void solve(){
char s[10];
int lca,a,b;
while(scanf("%s",s),s[0]!='D'){
Read(a),Read(b);
if(s[0]=='Q'){
lca=LCA(a,b);
printf("%d\n",max(query(lca,a),query(lca,b)));
}
else{
wt[id2v[a]]=b;
insert(root[bl[id2v[a]]],1,1,length[bl[id2v[a]]],pos[id2v[a]],b);
}
}
}
int main()
{
Read(T);
while(T--){
memset(fa,0,sizeof fa);
memset(adj,0,sizeof adj);
memset(tmax,0,sizeof tmax);
ttop=tmax;
ecnt=edge;
init();
solve();
}
}
动态树(LCT):
#include<cstdio>
#include<algorithm>
#include<cstring>
#define MAXN 10000
using namespace std;
int n,e2id[MAXN+10],T;
void Read(int &x){
char c;
while(c=getchar(),c!=EOF)
if(c>='0'&&c<='9'){
x=c-'0';
while(c=getchar(),c>='0'&&c<='9')
x=x*10+c-'0';
ungetc(c,stdin);
return;
}
}
struct node{
int val,mx,wt;
node *ch[2],*fa;
bool pre;
}splay_tree[MAXN+10];
struct nodedge{
int v,wt,pos;
nodedge *next;
}edge[MAXN*2+10],*ecnt=edge,*adj[MAXN+10];
inline void addedge(int u,int v,int wt,int pos){
nodedge *p=++ecnt;
p->v=v;
p->wt=wt;
p->next=adj[u];
p->pos=pos;
adj[u]=p;
}
inline void init(node *p){
p->ch[0]=p->ch[1]=0;
p->pre=0;
}
void dfs(int u,int dep,int fa){
node *x=&splay_tree[u],*y;
init(x);
x->val=dep;
for(nodedge *p=adj[u];p;p=p->next){
if(p->v!=fa){
e2id[p->pos]=p->v;
y=&splay_tree[p->v];
y->mx=y->wt=p->wt;
y->fa=x;
dfs(p->v,dep+1,u);
}
}
}
void read(){
Read(n);
int u,v,wt,i;
for(i=1;i<n;i++){
Read(u),Read(v),Read(wt);
addedge(u,v,wt,i);
addedge(v,u,wt,i);
}
init(&splay_tree[1]);
splay_tree[1].fa=0;
dfs(1,1,0);
}
inline int Get_max(node *p){
return p?p->mx:0;
}
inline void update(node *p){
p->mx=max(p->wt,max(Get_max(p->ch[0]),Get_max(p->ch[1])));
}
void Rotate(node *x,int d){
node *y=x->fa;
if(y->fa&&y->pre)
y->fa->ch[y==y->fa->ch[1]]=x;
x->fa=y->fa;
if(x->ch[d])
x->ch[d]->fa=y;
y->ch[!d]=x->ch[d];
x->ch[d]=y;
y->fa=x;
swap(x->pre,y->pre);
update(y);
}
void splay(node *x){
node *y,*z;
while(x->pre){
y=x->fa;
z=y->fa;
if(!z||!y->pre){
if(x==y->ch[0])
Rotate(x,1);
else
Rotate(x,0);
}
else{
if(y==z->ch[0])
if(x==y->ch[0]){
Rotate(y,1);
Rotate(x,1);
}
else{
Rotate(x,0);
Rotate(x,1);
}
else
if(x==y->ch[1]){
Rotate(y,0);
Rotate(x,0);
}
else{
Rotate(x,1);
Rotate(x,0);
}
}
}
update(x);
}
void access(int a){
node *x=&splay_tree[a],*y;
splay(x);
if(x->ch[1]){
x->ch[1]->pre=0;
x->ch[1]=0;
}
update(x);
while(1){
y=x->fa;
if(!y)
return;
splay(y);
if(y->ch[1])
y->ch[1]->pre=0;
y->ch[1]=x;
x->pre=1;
splay(x);
}
splay(x);
}
int query(int a){
node *x=&splay_tree[a],*y;
int ans;
splay(x);
if(!x->fa)
return Get_max(x->ch[1]);
if(x->ch[1]){
x->ch[1]->pre=0;
x->ch[1]=0;
}
update(x);
while(1){
y=x->fa;
splay(y);
ans=Get_max(y->ch[1]);
if(y->ch[1])
y->ch[1]->pre=0;
y->ch[1]=x;
x->pre=1;
if(!y->fa){
ans=max(ans,Get_max(x));
splay(x);
return ans;
}
splay(x);
}
}
void solve(){
char s[10];
int a,b;
while(scanf("%s",s),s[0]!='D')
if(s[0]=='Q'){
Read(a),Read(b);
access(a);
printf("%d\n",query(b));
}
else{
Read(a),Read(b);
access(e2id[a]);
splay_tree[e2id[a]].wt=b;
update(&splay_tree[e2id[a]]);
}
}
int main()
{
Read(T);
while(T--){
memset(adj,0,sizeof adj);
ecnt=edge;
read();
solve();
}
}