【BZOJ】【2157】旅游

LCT

　　直到动手写拆边为点的时候才发现根本不会写……去orz了一下Hzwer（话说这题应该也用不着LCT吧……下次再换种姿势写一遍好了）

 /**************************************************************
     Problem: 2157
     User: Tunix
     Language: C++
     Result: Accepted
     Time:668 ms
     Memory:2600 kb
 ****************************************************************/

 //BZOJ 2157
 #include<vector>
 #include<cstdio>
 #include<cstring>
 #include<cstdlib>
 #include<iostream>
 #include<algorithm>
 #define rep(i,n) for(int i=0;i<n;++i)
 #define F(i,j,n) for(int i=j;i<=n;++i)
 #define D(i,j,n) for(int i=j;i>=n;--i)
 using namespace std;
 int getint(){
     int v=,sign=; char ch=getchar();
     while(ch<''||ch>''){ if (ch=='-') sign=-; ch=getchar();}
     while(ch>=''&&ch<=''){ v=v*+ch-''; ch=getchar();}
     return v*=sign;
 }
 /******************tamplate*********************/
 const int N=,INF=~0u>>;
 int n,m,cnt;
 int ed[N];
 int c[N][],fa[N],v[N],sum[N],mn[N],mx[N];
 bool rev[N],Not[N];
 #define L c[x][0]
 #define R c[x][1]
 bool not_root(int x){
     return c[fa[x]][]==x || c[fa[x]][]==x;
 }
 void rever(int x){
     sum[x]=-sum[x]; v[x]=-v[x];
     swap(mn[x],mx[x]);
     mn[x]=-mn[x];mx[x]=-mx[x];
     Not[x]^=;
 }
 void Push_up(int x){
     mx[x]=max(mx[L],mx[R]);
     mn[x]=min(mn[L],mn[R]);
     if (x>n){
         mx[x]=max(mx[x],v[x]);
         mn[x]=min(mn[x],v[x]);
     }
     sum[x]=sum[L]+sum[R]+v[x];
 }
 void Push_down(int x){
     if (Not[x]){
         Not[x]^=;
         if (L) rever(L);
         if (R) rever(R);
     }
     if (rev[x]){
         rev[x]^=; rev[L]^=; rev[R]^=;
         swap(L,R);
     }
 }
 void rotate(int x){
     int y=fa[x],z=fa[y],l=c[y][]==x,r=l^;
     if (not_root(y)) c[z][c[z][]==y]=x;
     fa[x]=z; fa[y]=x; fa[c[x][r]]=y;
     c[y][l]=c[x][r]; c[x][r]=y;
     Push_up(y);
 }
 void preview(int x){
     if (not_root(x)) preview(fa[x]);
     Push_down(x);
 }
 void splay(int x){
     int y;
     for(preview(x);not_root(x);rotate(x))
         not_root(y=fa[x]) ? rotate(c[y][]==x^c[fa[y]][]==y ? x : y),:;
     Push_up(x);
 }
 void access(int x,int las=){
     for(;x;splay(x),c[x][]=las,las=x,x=fa[x]);
 }
 void makeroot(int x){
     access(x),splay(x),rev[x]^=;
 }
 void link(int x,int y){
     makeroot(x),fa[x]=y;
 }
 void query(int x,int y){
     makeroot(x),access(y),splay(y);
 }
 int main(){
     n=getint();
     F(i,,n) mn[i]=INF,mx[i]=-INF;
     int id=n;
     F(i,,n-){
         int x=getint()+,y=getint()+,w=getint();
         ed[i]=++id;
         link(x,id); link(y,id);
         v[id]=sum[id]=mx[id]=mn[id]=w;
     }
     m=getint();
     char cmd[]; int x,y;
     F(i,,m){
         scanf("%s",cmd);
         x=getint(); y=getint();
         if (cmd[]=='C'){
             splay(ed[x]),v[ed[x]]=y,Push_up(ed[x]);
         }
         else if(cmd[]=='N')
             query(x+,y+),rever(y+);
         else if(cmd[]=='S')
             query(x+,y+),printf("%d\n",sum[y+]);
         else if(cmd[]=='A')
             query(x+,y+),printf("%d\n",mx[y+]);
         else query(x+,y+),printf("%d\n",mn[y+]);
     }
     return ;
 }