bzoj2816 [ZJOI2012]网络

Description

http://www.lydsy.com/JudgeOnline/upload/zjoi2012.pdf
正解：$link-cut tree$。
$LCT$板子题，直接维护$10$个$LCT$就行了。
注意修改颜色操作，修改后的颜色可能与之前颜色相同。
  1 #include <bits/stdc++.h>
  2 #define il inline
  3 #define RG register
  4 #define ll long long
  5 #define N (10005)
  6 
  7 using namespace std;
  8 
  9 map<int,int> mp[N];
 10 
 11 int d[N][10],val[N],n,m,c,Q;
 12 
 13 il int gi(){
 14   RG int x=0,q=1; RG char ch=getchar();
 15   while ((ch<'0' || ch>'9') && ch!='-') ch=getchar();
 16   if (ch=='-') q=-1,ch=getchar();
 17   while (ch>='0' && ch<='9') x=x*10+ch-48,ch=getchar();
 18   return q*x;
 19 }
 20 
 21 struct Link_Cut_Tree{
 22   
 23   int ch[N][2],fa[N],sum[N],rev[N],st[N];
 24   
 25   il int isroot(RG int x){
 26     return ch[fa[x]][0]!=x && ch[fa[x]][1]!=x;
 27   }
 28   
 29   il void pushup(RG int x){
 30     sum[x]=max(val[x],max(sum[ch[x][0]],sum[ch[x][1]])); return;
 31   }
 32   
 33   il void pushdown(RG int x){
 34     rev[ch[x][0]]^=1,rev[ch[x][1]]^=1;
 35     swap(ch[x][0],ch[x][1]),rev[x]=0; return;
 36   }
 37   
 38   il void rotate(RG int x){
 39     RG int y=fa[x],z=fa[y],k=ch[y][0]==x;
 40     if (!isroot(y)) ch[z][ch[z][1]==y]=x;
 41     fa[x]=z,ch[y][k^1]=ch[x][k],fa[ch[x][k]]=y;
 42     ch[x][k]=y,fa[y]=x,pushup(y),pushup(x); return;
 43   }
 44   
 45   il void splay(RG int x){
 46     RG int top=0; st[++top]=x;
 47     for (RG int i=x;!isroot(i);i=fa[i]) st[++top]=fa[i];
 48     for (RG int i=top;i;--i) if (rev[st[i]]) pushdown(st[i]);
 49     while (!isroot(x)){
 50       RG int y=fa[x],z=fa[y];
 51       if (!isroot(y)) rotate((ch[z][0]==y)^(ch[y][0]==x)?x:y);
 52       rotate(x);
 53     }
 54     return;
 55   }
 56   
 57   il void access(RG int x){
 58     RG int t=0;
 59     while (x){
 60       splay(x),ch[x][1]=t;
 61       pushup(x),t=x,x=fa[x];
 62     }
 63     return;
 64   }
 65   
 66   il void makeroot(RG int x){
 67     access(x),splay(x),rev[x]^=1; return;
 68   }
 69   
 70   il void link(RG int x,RG int y){
 71     makeroot(x),fa[x]=y; return;
 72   }
 73   
 74   il void cut(RG int x,RG int y){
 75     makeroot(x),access(y),splay(y);
 76     ch[y][0]=fa[x]=0,pushup(y); return;
 77   }
 78   
 79   il int query(RG int x,RG int y){
 80     makeroot(x),access(y),splay(y); return sum[y];
 81   }
 82   
 83   il int find(RG int x){
 84     access(x),splay(x);
 85     while (ch[x][0]) x=ch[x][0]; return x;
 86   }
 87   
 88 }G[10];
 89 
 90 int main(){
 91 #ifndef ONLINE_JUDGE
 92   freopen("network.in","r",stdin);
 93   freopen("network.out","w",stdout);
 94 #endif
 95   n=gi(),m=gi(),c=gi(),Q=gi();
 96   for (RG int i=1;i<=n;++i) val[i]=gi();
 97   for (RG int i=1,u,v,w;i<=m;++i){
 98     u=gi(),v=gi(),w=gi(); if (u>v) swap(u,v);
 99     G[w].link(u,v),mp[u][v]=w,++d[u][w],++d[v][w];
100   }
101   while (Q--){
102     RG int op=gi();
103     if (!op){
104       RG int x=gi(),y=gi();
105       for (RG int i=0;i<c;++i) G[i].splay(x); val[x]=y;
106       for (RG int i=0;i<c;++i) G[i].pushup(x);
107     } else if (op==1){
108       RG int u=gi(),v=gi(),w=gi(),k; if (u>v) swap(u,v);
109       if (!mp[u].count(v)){ puts("No such edge."); continue; } k=mp[u][v];
110       if (k!=w && (d[u][w]>=2 || d[v][w]>=2)) puts("Error 1.");
111       else if (k!=w && G[w].find(u)==G[w].find(v)) puts("Error 2."); else{
112     RG int k=mp[u][v]; --d[u][k],--d[v][k],++d[u][w],++d[v][w];
113     G[k].cut(u,v),G[w].link(u,v),mp[u][v]=w,puts("Success.");
114       }
115     } else{
116       RG int w=gi(),u=gi(),v=gi();
117       if (G[w].find(u)!=G[w].find(v)) puts("-1");
118       else printf("%d
",G[w].query(u,v));
119     }
120   }
121   return 0;
122 }