【BZOJ2157】旅游 LCT

  1 #include <iostream>
  2 #include <cstdio>
  3 #define inf 0x7fffffff
  4 #define N 20010
  5 #define M 20010
  6 using namespace std;
  7 int n,m;
  8 struct node *null;
  9 struct node 
 10 {
 11     node *fa,*ch[2];
 12     //node(int x,int flag);
 13     int maxn,minn,data,sum;
 14     bool rev,rev_data,ie;
 15     bool chr() {return this==fa->ch[1];}
 16     bool isrt() {return this!=fa->ch[1] && this !=fa->ch[0];}
 17     void setc(node *x,int t) {this->ch[t]=x; x->fa=this;}
 18     void push_up();
 19     void push_down();
 20 }pool[N+M],*pt=pool,*e[M],*p[N];
 21 void node::push_up()
 22 {
 23     if (this==null) return;
 24     sum=ch[1]->sum+ch[0]->sum+data*ie;
 25     maxn=max(ch[1]->maxn,ch[0]->maxn); if (ie) maxn=max(maxn,data);
 26     minn=min(ch[1]->minn,ch[0]->minn); if (ie) minn=min(minn,data); 
 27 }
 28 void node::push_down()
 29 {
 30     if (this==null) return;
 31     if (!isrt()) fa->push_down();
 32     if (rev)
 33     {
 34         if (ch[0]!=null) ch[0]->rev^=1;
 35         if (ch[1]!=null) ch[1]->rev^=1;
 36         swap(ch[0],ch[1]);
 37         rev=0;
 38     }
 39     if (rev_data)
 40     {
 41         if (ch[0]!=null)
 42         {
 43             int k=ch[0]->maxn;
 44             ch[0]->rev_data^=1;
 45             ch[0]->data=-ch[0]->data;
 46             ch[0]->sum=-ch[0]->sum;
 47             ch[0]->maxn=-ch[0]->minn;
 48             ch[0]->minn=-k;
 49         }
 50         if (ch[1]!=null)
 51         {
 52             int k=ch[1]->maxn;
 53             ch[1]->rev_data^=1;
 54             ch[1]->sum=-ch[1]->sum;
 55             ch[1]->maxn=-ch[1]->minn;
 56             ch[1]->minn=-k;
 57             ch[1]->data=-ch[1]->data;
 58         }
 59     //    swap(ch[0],ch[1]);// 注意！！！ 
 60         rev_data=0;
 61     }
 62 }
 63 namespace LCT
 64 {
 65     node *NewNode(int x,int flag) 
 66     {
 67         node *r=pt++;
 68         r->fa=r->ch[0]=r->ch[1]=null;
 69         r->data=r->sum=x; r->ie=flag;
 70         if  (flag) r->maxn=r->minn=x;
 71         else r->maxn=-inf,r->minn=inf;
 72         r->rev=r->rev_data=0;
 73         return r;
 74     }
 75     void rotate(node *x)
 76     {
 77         node *r=x->fa;
 78         if (r==null || x==null) return;
 79         x->push_down(); r->push_down();
 80         bool t=x->chr();
 81         if (r->isrt()) x->fa=r->fa; // ！！！在这里坑了好几次了 
 82         else r->fa->setc(x,r->chr());
 83         r->setc(x->ch[t^1],t);
 84         x->setc(r,!t);
 85         r->push_up(); x->push_up();
 86     }
 87     void Splay(node *x)
 88     {
 89         //if (x==null) return;
 90         x->push_down();
 91         for (;!x->isrt();rotate(x))
 92             if (!x->fa->isrt())
 93                 if (x->chr()==x->fa->chr()) rotate(x->fa);
 94                 else rotate(x);
 95         x->push_up();
 96     }    
 97     void Access(node *x)
 98     {
 99         node *r=null;
100         for (;x!=null;r=x,x=x->fa)
101         {
102             Splay(x);
103             x->ch[1]=r;
104         }
105     }
106     void MoveRoot(node *x) {Access(x); Splay(x); x->rev^=1;}
107     void Split(node *x,node *y) {MoveRoot(x); Access(y); Splay(y);}
108     void Link(node *x,node *y) {MoveRoot(x); x->fa=y;}
109     void Cut(node *x,node *y) {Split(x,y); y->ch[0]->fa=null; y->ch[0]=null;}
110     void Change(node *x,int v) {Splay(x); x->data=v; x->push_up();}
111     void Data_Rev(node *x,node *y) {Split(x,y); int k=y->maxn; y->data=-y->data; y->sum=-y->sum; y->maxn=-y->minn; y->minn=-k; y->rev_data^=1; }
112     int Query_Sum(node *x,node *y) {Split(x,y); return y->sum;}
113     int Query_Max(node *x,node *y) {Split(x,y); return y->maxn;}
114     int Query_Min(node *x,node *y) {Split(x,y); return y->minn;}
115 }
116 inline int read()
117 {
118     char c;
119     int ans=0,f=1;
120     while (!isdigit(c=getchar())) {if (c==‘-‘) f=-1;}
121     ans=c-‘0‘;
122     while (isdigit(c=getchar())) ans=ans*10+c-‘0‘;
123     return ans*f;
124 }
125 void init() 
126 {
127     null=pt++;
128     null->fa=null->ch[0]=null->ch[1]=null;
129     null->data=null->sum=0;
130     null->rev=null->rev_data=null->ie=0;
131     null->maxn=-inf; null->minn=inf;
132 }
133 using namespace LCT;
134 int main()
135 {
136 //    freopen("travel.in","r",stdin);
137 //    freopen("travel.out","w",stdout);
138     int x,y,z;
139     n=read();
140     init();
141     for (int i=0;i<n;i++) p[i]=NewNode(0,0);
142     for (int i=1;i<n;i++)
143     {
144         x=read(); y=read(); z=read();
145         e[i]=NewNode(z,1);
146         Link(p[x],e[i]);Link(e[i],p[y]);
147     }
148     m=read();
149     char s[10];
150     for (int i=1;i<=m;i++)
151     {
152         scanf("%s",s);
153         x=read(); y=read();
154         if (s[0]==‘C‘) Change(e[x],y);
155         if (s[0]==‘N‘) Data_Rev(p[x],p[y]);
156         if (s[0]==‘S‘) printf("%d\n",Query_Sum(p[x],p[y]));
157         if (s[0]==‘M‘)
158             if (s[1]==‘A‘)    printf("%d\n",Query_Max(p[x],p[y]));
159             else printf("%d\n",Query_Min(p[x],p[y]));
160     }
161     return 0;
162 }