hysbz 2243

来源：互联网发布：如何学好单片机编辑：程序博客网时间：2024/05/22 15:11
#include<iostream>  #include<cstdio>  #include<cstring>  #include<queue>  #include<set>  #include<map>  #include<vector>  #include<stack>  #include<cmath>  #include<string>  #include<algorithm>  using namespace std;  typedef long long ll;  const int sigma_size=26;  const int N=100+50;  const int MAXN=100000+50;  const int inf=0x3fffffff;  const double eps=1e-8;  const int mod=100000000+7;  #define L(x) (x<<1)  #define R(x) (x<<1|1)  #define PII pair<int, int>  #define mk(x,y) make_pair((x),(y))  int n,m,edge_cnt,cnt,Lc,Rc;  char str[N];  int col[MAXN],head[MAXN],sz[MAXN],dep[MAXN],fa[MAXN],son[MAXN],top[MAXN],pos[MAXN];  struct Edge{      int u,v,next;  }edge[MAXN<<1];  struct node{      int l,r;      int num,tag,lc,rc;  }segtree[MAXN<<2];  void init(){      edge_cnt=cnt=0;      memset(head,-1,sizeof(head));  }  void addedge(int u,int v){      edge[edge_cnt].u=u; edge[edge_cnt].v=v;      edge[edge_cnt].next=head[u]; head[u]=edge_cnt++;  }  void dfs1(int u,int pre,int depth){      sz[u]=1; fa[u]=pre; son[u]=0; dep[u]=depth;      for(int i=head[u];i!=-1;i=edge[i].next){          int v=edge[i].v;          if(v == pre)              continue;          dfs1(v,u,depth+1);          sz[u]+=sz[v];          if(sz[son[u]]<sz[v])              son[u]=v;      }  }  void dfs2(int u,int tp){      pos[u]=++cnt; top[u]=tp;      if(son[u]!=0)          dfs2(son[u],top[u]);      for(int i=head[u];i!=-1;i=edge[i].next){          int v=edge[i].v;          if(v == fa[u] || v == son[u])              continue;          dfs2(v,v);      }  }  void push_down(int rt){      if(segtree[rt].tag){          segtree[L(rt)].tag=segtree[R(rt)].tag=segtree[rt].tag;          segtree[L(rt)].num=segtree[R(rt)].num=1;          segtree[L(rt)].lc=segtree[L(rt)].rc=segtree[rt].lc;          segtree[R(rt)].lc=segtree[R(rt)].rc=segtree[rt].lc;          segtree[rt].tag=0;      }  }  void push_up(int rt){      segtree[rt].lc=segtree[L(rt)].lc; segtree[rt].rc=segtree[R(rt)].rc;      int ans=segtree[L(rt)].num+segtree[R(rt)].num;      if(segtree[L(rt)].rc == segtree[R(rt)].lc)          ans--;      segtree[rt].num=ans;  }  void build(int rt,int l,int r){      segtree[rt].l=l; segtree[rt].r=r; segtree[rt].num=0;      if(l == r)          return ;      int mid=(l+r)>>1;      build(L(rt),l,mid); build(R(rt),mid+1,r);  }  void update(int rt,int l,int r,int x){      if(segtree[rt].l == l && segtree[rt].r == r){          segtree[rt].num=segtree[rt].tag=1;          segtree[rt].lc=segtree[rt].rc=x;          return ;      }      push_down(rt);      int mid=(segtree[rt].l+segtree[rt].r)>>1;      if(r<=mid)          update(L(rt),l,r,x);      else if(l>mid)          update(R(rt),l,r,x);      else {          update(L(rt),l,mid,x); update(R(rt),mid+1,r,x);      }      push_up(rt);  }  int query(int rt,int l,int r,int L,int R){      if(segtree[rt].l == L)          Lc=segtree[rt].lc;      if(segtree[rt].r == R)          Rc=segtree[rt].rc;      if(segtree[rt].l == l && segtree[rt].r == r)          return segtree[rt].num;      push_down(rt);      int mid=(segtree[rt].l+segtree[rt].r)>>1;      if(r<=mid)          return query(L(rt),l,r,L,R);      else if(l>mid)          return query(R(rt),l,r,L,R);      else{          int ans=query(L(rt),l,mid,L,R)+query(R(rt),mid+1,r,L,R);          if(segtree[L(rt)].rc == segtree[R(rt)].lc)              ans--;          return ans;      }      push_up(rt);  }  int solve(int u,int v,int id,int c){      int ans=0;      if(id == 1){          while(top[u]!=top[v]){              if(dep[top[u]]<dep[top[v]])                  swap(u,v);              update(1,pos[top[u]],pos[u],c);              u=fa[top[u]];          }          if(dep[u]>dep[v])              swap(u,v);          update(1,pos[u],pos[v],c);      }      else{          //printf("u=%d v=%d pos[u]=%d pos[v]=%d\n",u,v,pos[u],pos[v]);          int ans1=-1,ans2=-1; //记录上次链的左端的颜色          while(top[u]!=top[v]){              if(dep[top[u]]<dep[top[v]]){                  swap(u,v); swap(ans1,ans2);              }              ans+=query(1,pos[top[u]],pos[u],pos[top[u]],pos[u]);              if(Rc == ans1)                  ans--;             // printf("u=%d top[u]=%d Lc=%d Rc=%d ans=%d\n",u,top[u],Lc,Rc,ans);              ans1=Lc; u=fa[top[u]];          }          if(dep[u]<dep[v]){              swap(u,v); swap(ans1,ans2);          }          ans+=query(1,pos[v],pos[u],pos[v],pos[u]);          if(Rc == ans1)              ans--;          if(Lc == ans2)              ans--;          //printf("u=%d v=%d Lc=%d Rc=%d ans=%d\n",u,v,Lc,Rc,ans);      }      return ans;  }  int main(){      //freopen("in.txt","r",stdin);      while(~scanf("%d%d",&n,&m)){          init();          for(int i=1;i<=n;i++)              scanf("%d",&col[i]);          for(int i=1;i<n;i++){              int u,v;              scanf("%d%d",&u,&v);              addedge(u,v); addedge(v,u);          }          dfs1(1,1,1); dfs2(1,1); build(1,1,n);          //<F9>printf("%d %d\n",son[1],son[2]);          /*for(int i=1;i<=n;i++)             printf("top[i]=%d pos[i]%d\n",top[i],pos[i]);         printf("---------------------------------------\n");         printf("\n");*/          for(int i=1;i<=n;i++)              update(1,pos[i],pos[i],col[i]);          while(m--){              scanf("%s",str);              int u,v;              if(str[0] == 'C'){                  int c;                  scanf("%d%d%d",&u,&v,&c);                  solve(u,v,1,c);              }              else{                  int u,v;                  scanf("%d%d",&u,&v);                  printf("%d\n",solve(u,v,2,0));                  //printf("--------------------------------------\n");              }          }      }      return 0;  }
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