省选模版复习——LCT

来源：互联网发布：2015年老龄化数据编辑：程序博客网时间：2024/05/18 01:02
bzoj2157 LCT裸题
#include <cstdio>#include <cstring>#include <algorithm> using namespace std;const int INF=1e9;const int Maxn=40005;int son[Maxn][2],sum[Maxn],minx[Maxn],maxx[Maxn];int inv[Maxn],rev[Maxn],w[Maxn],fa[Maxn];int n,m,x,y,i,a,u,v; #define isroot(x) ( !((son[fa[x]][0]==x)||(son[fa[x]][1]==x)) )void push1(int x){  swap(son[x][0],son[x][1]);  if (son[x][0]) rev[son[x][0]] ^= 1;  if (son[x][1]) rev[son[x][1]] ^= 1;  rev[x] = 0;} void push2(int x){  int L = son[x][0], R = son[x][1];  if (L){    sum[L] = -sum[L];    swap(minx[L],maxx[L]);    minx[L] = -minx[L];    maxx[L] = -maxx[L];    inv[L] ^= 1;    if (L>n) w[L]=-w[L];  }  if (R){    sum[R] = -sum[R];    swap(minx[R],maxx[R]);    minx[R] = -minx[R];    maxx[R] = -maxx[R];    inv[R] ^= 1;    if (R>n) w[R]=-w[R];  }  inv[x] = 0;} void update(int x){  sum[x] = sum[son[x][0]]+sum[son[x][1]]+w[x];  minx[x] = min(minx[son[x][0]], minx[son[x][1]]);  maxx[x] = max(maxx[son[x][0]], maxx[son[x][1]]);  if (x>n){    minx[x] = min(w[x], minx[x]);    maxx[x] = max(w[x], maxx[x]);  }} void rotate(int x,int ft,int K){  if (!isroot(ft)){    if (son[fa[ft]][0]==ft)      son[fa[ft]][0] = x;    else son[fa[ft]][1] = x;  } fa[x] = fa[ft];     if (son[x][K^1]) fa[son[x][K^1]]=ft;  son[ft][K] = son[x][K^1];  son[x][K^1] = ft; fa[ft] = x;  update(ft);} void Splay(int x){  int ft, gf;  while (!isroot(x)){    ft = fa[x]; gf = fa[ft];    if (rev[gf]) push1(gf); if (inv[gf]) push2(gf);    if (rev[ft]) push1(ft); if (inv[ft]) push2(ft);    if (rev[x]) push1(x); if (inv[x]) push2(x);    if (isroot(ft)){      if (son[ft][0]==x) rotate(x,ft,0);      if (son[ft][1]==x) rotate(x,ft,1);    } else    {      if (son[ft][0]==x && son[gf][0]==ft) rotate(ft,gf,0), rotate(x,ft,0);      if (son[ft][1]==x && son[gf][1]==ft) rotate(ft,gf,1), rotate(x,ft,1);      if (son[ft][0]==x && son[gf][1]==ft) rotate(x,ft,0), rotate(x,gf,1);      if (son[ft][1]==x && son[gf][0]==ft) rotate(x,ft,1), rotate(x,gf,0);    }  }  if (rev[x]) push1(x);  if (inv[x]) push2(x);  update(x);} void access(int x){  int t = 0;  while (x){    Splay(x);    son[x][1] = t;    update(x);    t = x; x = fa[x];  }} void makeroot(int x)  { access(x); Splay(x); rev[x]^=1; } void Link(int x,int y)  { makeroot(x); fa[x]=y; access(x); } void cut(int x,int y){  makeroot(x); access(y); Splay(y);  son[y][0] = 0; fa[x] = 0;  Splay(x); Splay(y);} int main(){  //freopen("2157.in","r",stdin);  //freopen("2157.out","w",stdout);  scanf("%d",&n);  minx[0] = INF; maxx[0] = -INF;  for (i=1;i<n;i++){    scanf("%d%d%d",&x,&y,&w[n+i]);    x++; y++;    Link(x,n+i); Link(y,n+i);  }  scanf("%d\n",&m);  char S[5];  while (m--){    scanf("%s",S);    if (S[0]=='C'){      scanf("%d%d\n",&i,&a);      makeroot(i+n);      w[i+n] = a;      update(i+n);    } else    if (S[0]=='N'){      scanf("%d%d\n",&u,&v);      u++; v++;      makeroot(u);      access(v);      Splay(v);             sum[v] = -sum[v];      swap(minx[v],maxx[v]);      minx[v] = -minx[v];      maxx[v] = -maxx[v];      inv[v] ^= 1;           } else    if (S[0]=='S'){      scanf("%d%d\n",&u,&v);      u++; v++;      makeroot(u);      access(v);      Splay(v);      printf("%d\n",sum[v]);    } else    if (S[1]=='A'){      scanf("%d%d\n",&u,&v);      u++; v++;      makeroot(u);      access(v);      Splay(v);      printf("%d\n",maxx[v]);    } else    {      scanf("%d%d\n",&u,&v);      u++; v++;      makeroot(u);      access(v);      Splay(v);      printf("%d\n",minx[v]);    }  }  return 0;}
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