【BZOJ1036】树的统计Count（树链剖分，LCT）

题意：一棵树上有n个节点，编号分别为1到n，每个节点都有一个权值w。我们将以下面的形式来要求你对这棵树完成
一些操作：

I. CHANGE u t : 把结点u的权值改为t

II. QMAX u v: 询问从点u到点v的路径上的节点的最大权值

I

II. QSUM u v: 询问从点u到点v的路径上的节点的权值和

注意：从点u到点v的路径上的节点包括u和v本身

1<=n<=30000，0<=q<=200000；中途操作中保证每个节点的权值w在-30000到30000之间。

 

思路：树链剖分，单点修改，区间查询和与最大值。

  1 var t1,t2,next,vet,head,dep,flag,tid,fa,top,size,id,son,a
  2    :array[1..200000]of longint;
  3     n,m,i,j,k,k1,t,x,y,tot,time,q,len,f:longint;
  4     ch:string;
  5 
  6 procedure add(a,b:longint);
  7 begin
  8  inc(tot);
  9  next[tot]:=head[a];
 10  vet[tot]:=b;
 11  head[a]:=tot;
 12 end;
 13 
 14 function max(x,y:longint):longint;
 15 begin
 16  if x>y then exit(x);
 17  exit(y);
 18 end;
 19 
 20 procedure dfs1(u,fath,depth:longint);
 21 var e,v,maxsize:longint;
 22 begin
 23  flag[u]:=1; dep[u]:=depth; fa[u]:=fath;
 24  e:=head[u];
 25  flag[u]:=1; size[u]:=1;
 26  maxsize:=0; son[u]:=0;
 27  while e<>0 do
 28  begin
 29   v:=vet[e];
 30   if flag[v]=0 then
 31   begin
 32   // h[e]:=1;
 33    dfs1(v,u,depth+1);
 34    size[u]:=size[u]+size[v];
 35    if size[v]>maxsize then
 36    begin
 37     maxsize:=size[v];
 38     son[u]:=v;
 39    end;
 40   end;
 41   e:=next[e];
 42  end;
 43 end;
 44 
 45 procedure dfs2(u,ance:longint);
 46 var e,v:longint;
 47 begin
 48  flag[u]:=1; inc(time); tid[u]:=time; id[time]:=u; top[u]:=ance;
 49  if son[u]>0 then dfs2(son[u],ance);
 50  e:=head[u];
 51  while e<>0 do
 52  begin
 53   v:=vet[e];
 54   if flag[v]=0 then dfs2(v,v);
 55   e:=next[e];
 56  end;
 57 end;
 58 
 59 procedure build(l,r,p:longint);
 60 var mid:longint;
 61 begin
 62  if l=r then
 63  begin
 64   t1[p]:=a[id[l]];
 65   t2[p]:=a[id[l]];
 66   exit;
 67  end;
 68  mid:=(l+r)>>1;
 69  build(l,mid,p<<1);
 70  build(mid+1,r,p<<1+1);
 71  t1[p]:=max(t1[p<<1],t1[p<<1+1]);
 72  t2[p]:=t2[p<<1]+t2[p<<1+1];
 73 end;
 74 
 75 procedure update(l,r,x,v,p:longint);
 76 var mid:longint;
 77 begin
 78  if l=r then
 79  begin
 80   t1[p]:=v; t2[p]:=v;
 81   exit;
 82  end;
 83  mid:=(l+r)>>1;
 84  if x<=mid then update(l,mid,x,v,p<<1);
 85  if x>mid then update(mid+1,r,x,v,p<<1+1);
 86  t1[p]:=max(t1[p<<1],t1[p<<1+1]);
 87  t2[p]:=t2[p<<1]+t2[p<<1+1];
 88 end;
 89 
 90 function querymax(l,r,x,y,p:longint):longint;
 91 var mid,t:longint;
 92 begin
 93  if (l=x)and(r=y) then exit(t1[p]);
 94  mid:=(l+r)>>1;
 95  t:=-maxlongint;
 96  if y<=mid then t:=querymax(l,mid,x,y,p<<1)
 97   else if x>mid then t:=querymax(mid+1,r,x,y,p<<1+1)
 98   else t:=max(querymax(l,mid,x,mid,p<<1),querymax(mid+1,r,mid+1,y,p<<1+1));
 99  exit(t);
100 end;
101 
102 function querysum(l,r,x,y,p:longint):longint;
103 var mid,t:longint;
104 begin
105  if (l=x)and(r=y) then exit(t2[p]);
106  mid:=(l+r)>>1;
107  t:=0;
108  if y<=mid then t:=querysum(l,mid,x,y,p<<1)
109   else if x>mid then t:=querysum(mid+1,r,x,y,p<<1+1)
110    else t:=querysum(l,mid,x,mid,p<<1)+querysum(mid+1,r,mid+1,y,p<<1+1);
111  exit(t);
112 end;
113 
114 procedure swap(var x,y:longint);
115 var t:longint;
116 begin
117  t:=x; x:=y; y:=t;
118 end;
119 
120 function askmax(x,y:longint):longint;
121 var f1,f2,t:longint;
122 begin
123  t:=-maxlongint;
124  f1:=top[x]; f2:=top[y];
125  while f1<>f2 do
126  begin
127   if dep[f1]<dep[f2] then
128   begin
129    swap(f1,f2); swap(x,y);
130   end;
131   t:=max(t,querymax(1,n,tid[f1],tid[x],1));
132   x:=fa[f1]; f1:=top[x];
133  end;
134  if dep[x]>dep[y] then swap(x,y);
135  t:=max(t,querymax(1,n,tid[x],tid[y],1));
136  exit(t);
137 end;
138 
139 function asksum(x,y:longint):longint;
140 var f1,f2,t:longint;
141 begin
142  t:=0;
143  f1:=top[x]; f2:=top[y];
144  while f1<>f2 do
145  begin
146   if dep[f1]<dep[f2] then
147   begin
148    swap(f1,f2); swap(x,y);
149   end;
150   t:=t+querysum(1,n,tid[f1],tid[x],1);
151   x:=fa[f1]; f1:=top[x];
152  end;
153  if dep[x]>dep[y] then swap(x,y);
154  t:=t+querysum(1,n,tid[x],tid[y],1);
155  exit(t);
156 end;
157 
158 begin
159  //assign(input,'bzoj1036.in'); reset(input);
160  //assign(output,'bzoj1036.out'); rewrite(output);
161  readln(n);
162  for i:=1 to n-1 do
163  begin
164   readln(x,y);
165   add(x,y);
166   add(y,x);
167  end;
168  for i:=1 to n do read(a[i]);
169  dfs1(1,-1,1);
170  fillchar(flag,sizeof(flag),0);
171  dfs2(1,1);
172  fillchar(t1,sizeof(t1),$8f);
173  build(1,n,1);
174  readln(q);
175  for i:=1 to q do
176  begin
177   readln(ch);
178   x:=0; y:=0;
179   for j:=1 to length(ch) do
180    if ch[j]=' ' then break;
181   while ch[j]=' ' do inc(j);
182   f:=1;
183   while ch[j]<>' ' do
184   begin
185   // if ch[j]='-' then f:=-1;
186    if (ch[j]>='0')and(ch[j]<='9') then x:=x*10+ord(ch[j])-ord('0');
187    inc(j);
188   end;
189 
190   while ch[j]=' ' do inc(j);
191   while (j<=length(ch))and(ch[j]<>' ') do
192   begin
193    if ch[j]='-' then f:=-1;
194    if (ch[j]>='0')and(ch[j]<='9') then y:=y*10+ord(ch[j])-ord('0');
195    inc(j);
196   end;
197   if f=-1 then y:=-y;
198 
199 
200 
201   if ch[1]='C' then update(1,n,tid[x],y,1);
202   if (ch[1]='Q')and(ch[2]='M') then writeln(askmax(x,y));
203   if (ch[1]='Q')and(ch[2]='S') then writeln(asksum(x,y));
204  {  if ch[1]='C' then
205   begin
206    delete(ch,1,7);
207    val(copy(ch,1,pos(' ',ch)-1),x);
208    val(copy(ch,pos(' ',ch)+1,length(ch)-pos(' ',ch)),y);
209    update(1,n,tid[x],y,1);
210   end
211    else if ch[2]='M' then
212    begin
213     delete(ch,1,5);
214     val(copy(ch,1,pos(' ',ch)-1),x);
215     val(copy(ch,pos(' ',ch)+1,length(ch)-pos(' ',ch)),y);
216     writeln(askmax(x,y));
217    end
218     else
219     begin
220      delete(ch,1,5);
221      val(copy(ch,1,pos(' ',ch)-1),x);
222      val(copy(ch,pos(' ',ch)+1,length(ch)-pos(' ',ch)),y);
223      writeln(asksum(x,y));
224 
225     end;    }
226 
227  end;
228  //close(input);
229  //close(output);
230 end.

 这是LCT写法，这种没有结构变化的树上操作还是写树剖吧，BZOJ上LCT只能卡着时限过

  1 var c:array[0..50000,0..1]of longint;
  2     mx,sum,w:array[0..50000]of int64;
  3     fa,rev,q,a,b:array[0..50000]of longint;
  4     n,m,i,x,y,k,que,j,f,top,t:longint;
  5     ch:string;
  6 
  7 procedure update(x:longint);
  8 var l,r:longint;
  9 begin
 10  l:=c[x,0]; r:=c[x,1];
 11  sum[x]:=sum[l]+sum[r]+w[x];
 12  mx[x]:=w[x];
 13  if mx[l]>mx[x] then mx[x]:=mx[l];
 14  if mx[r]>mx[x] then mx[x]:=mx[r];
 15 //mx[x]:=max(w[x],max(mx[l],mx[r]));
 16 end;
 17 
 18 function isroot(x:longint):boolean;
 19 begin
 20  if (c[fa[x],0]<>x)and(c[fa[x],1]<>x) then exit(true);
 21  exit(false);
 22 end;
 23 
 24 
 25 
 26 procedure pushdown(x:longint);
 27 var l,r:longint;
 28 begin
 29  l:=c[x,0]; r:=c[x,1];
 30  if rev[x]=1 then
 31  begin
 32   rev[x]:=rev[x] xor 1; rev[l]:=rev[l] xor 1; rev[r]:=rev[r] xor 1;
 33   //swap(c[x,0],c[x,1]);
 34   t:=c[x,0]; c[x,0]:=c[x,1]; c[x,1]:=t;
 35  end;
 36 end;
 37 
 38 procedure rotate(x:longint);
 39 var y,z,l,r:longint;
 40 begin
 41  y:=fa[x]; z:=fa[y];
 42  if c[y,1]=x then l:=1
 43   else l:=0; r:=1-l;
 44  if not((c[fa[y],0]<>y)and(c[fa[y],1]<>y)) then
 45   if c[z,1]=y then c[z,1]:=x
 46    else c[z,0]:=x;
 47  fa[c[x,r]]:=y; fa[y]:=x; fa[x]:=z;
 48  c[y,l]:=c[x,r]; c[x,r]:=y;
 49  update(y);
 50  update(x);
 51 end;
 52 
 53 procedure splay(x:longint);
 54 var k,y,z,i:longint;
 55 begin
 56  inc(top); q[top]:=x;
 57  k:=x;
 58  while not((c[fa[k],0]<>k)and(c[fa[k],1]<>k)) do
 59  begin
 60   inc(top); q[top]:=fa[k];
 61   k:=fa[k];
 62  end;
 63  while top>0 do
 64  begin
 65   pushdown(q[top]);
 66   dec(top);
 67  end;
 68 
 69  while not((c[fa[x],0]<>x)and(c[fa[x],1]<>x)) do
 70  begin
 71   y:=fa[x]; z:=fa[y];
 72   if not((c[fa[y],0]<>y)and(c[fa[y],1]<>y)) then
 73   begin
 74    if (c[y,0]=x)xor(c[z,0]=y) then rotate(x)
 75     else rotate(y);
 76   end;
 77   rotate(x);
 78  end;
 79 end;
 80 
 81 procedure access(x:longint);
 82 var t:longint;
 83 begin
 84  t:=0;
 85  while x>0 do
 86  begin
 87   splay(x); c[x,1]:=t; update(x);
 88   t:=x; x:=fa[x];
 89  end;
 90 end;
 91 
 92 procedure makeroot(x:longint);
 93 begin
 94  access(x); splay(x); rev[x]:=rev[x] xor 1;
 95 end;
 96 
 97 procedure link(x,y:longint);
 98 begin
 99  makeroot(x); fa[x]:=y;
100 end;
101 
102 procedure split(x,y:longint);
103 begin
104  makeroot(x); access(y); splay(y);
105 end;
106 
107 begin
108  assign(input,'bzoj1036.in'); reset(input);
109  assign(output,'bzoj1036.out'); rewrite(output);
110  readln(n);
111  mx[0]:=-maxlongint div 2;
112 
113  for i:=1 to n-1 do readln(a[i],b[i]);
114  for i:=1 to n do
115  begin
116   read(w[i]); sum[i]:=w[i]; mx[i]:=w[i];
117  end;
118  for i:=1 to n-1 do link(a[i],b[i]);
119  readln(que);
120  for i:=1 to que do
121  begin
122   readln(ch);
123   x:=0; y:=0;
124   for j:=1 to length(ch) do
125    if ch[j]=' ' then break;
126   while ch[j]=' ' do inc(j);
127   f:=1;
128   while ch[j]<>' ' do
129   begin
130    if (ch[j]>='0')and(ch[j]<='9') then x:=x*10+ord(ch[j])-ord('0');
131    inc(j);
132   end;
133 
134   while ch[j]=' ' do inc(j);
135   while (j<=length(ch))and(ch[j]<>' ') do
136   begin
137    if ch[j]='-' then f:=-1;
138    if (ch[j]>='0')and(ch[j]<='9') then y:=y*10+ord(ch[j])-ord('0');
139    inc(j);
140   end;
141   if f=-1 then y:=-y;
142 
143 
144 
145   if ch[1]='C' then
146   begin
147    splay(x);
148    w[x]:=y;
149    update(x);
150   end;
151   if (ch[1]='Q')and(ch[2]='M') then
152   begin
153    split(x,y);
154    writeln(mx[y]);
155   end;
156 
157   if (ch[1]='Q')and(ch[2]='S') then
158   begin
159    split(x,y);
160    writeln(sum[y]);
161   end;
162 
163  end;
164  close(input);
165  close(output);
166 end.

 UPD（2018.9.19）：C++ 树链剖分写法

  1 #include<cstdio>
  2 #include<cstring>
  3 #include<string>
  4 #include<cmath>
  5 #include<iostream>
  6 #include<algorithm>
  7 #include<map>
  8 #include<set>
  9 #include<queue>
 10 #include<vector>
 11 using namespace std;
 12 typedef long long ll;
 13 typedef unsigned int uint;
 14 typedef unsigned long long ull;
 15 typedef pair<int,int> PII;
 16 typedef vector<int> VI;
 17 #define fi first
 18 #define se second 
 19 #define MP make_pair
 20 #define N   210000
 21 #define MOD 1000000007
 22 #define eps 1e-8 
 23 #define pi acos(-1)
 24 #define oo 1e9
 25 
 26 int mx[N],sum[N],a[N],head[N],vet[N],nxt[N],top[N],tid[N],id[N],
 27     fa[N],size[N],son[N],dep[N],flag[N],n,cnt,tot;
 28 char ch[10];
 29 
 30 int read()
 31 { 
 32    int v=0,f=1;
 33    char c=getchar();
 34    while(c<48||57<c) {if(c=='-') f=-1; c=getchar();}
 35    while(48<=c&&c<=57) v=(v<<3)+v+v+c-48,c=getchar();
 36    return v*f;
 37 }
 38 
 39 void add(int a,int b)
 40 {
 41     nxt[++tot]=head[a];
 42     vet[tot]=b;
 43     head[a]=tot;
 44 }
 45 
 46 void dfs1(int u)
 47 {
 48     flag[u]=1; size[u]=1; 
 49     int maxsize=0; son[u]=0;
 50     int e=head[u];
 51     while(e)
 52     {
 53         int v=vet[e];
 54         if(!flag[v])
 55         {
 56             fa[v]=u;
 57             dep[v]=dep[u]+1;
 58             dfs1(v);
 59             size[u]+=size[v];
 60             if(size[v]>maxsize)
 61             {
 62                 maxsize=size[v];
 63                 son[u]=v;
 64             }
 65         }
 66         e=nxt[e];
 67     }
 68 }
 69 
 70 void dfs2(int u,int ance)
 71 {
 72      flag[u]=1;
 73      tid[u]=++cnt; id[cnt]=u; top[u]=ance;
 74      if(son[u]) dfs2(son[u],ance);
 75      int e=head[u];
 76      while(e)
 77      {
 78          int v=vet[e];
 79          if(!flag[v]) dfs2(v,v);
 80          e=nxt[e];
 81      }
 82 }
 83 
 84 void pushup(int p)
 85 {
 86     mx[p]=max(mx[p<<1],mx[p<<1|1]);
 87     sum[p]=sum[p<<1]+sum[p<<1|1];
 88 }
 89 
 90 void build(int l,int r,int p)
 91 {
 92     if(l==r)
 93     {
 94         mx[p]=sum[p]=a[id[l]];
 95         return;
 96     }
 97     int mid=(l+r)>>1;
 98     build(l,mid,p<<1);
 99     build(mid+1,r,p<<1|1);
100     pushup(p);
101 }
102 
103 void update(int l,int r,int x,int v,int p)
104 {
105     if(l==r)
106     {
107         mx[p]=sum[p]=v;
108         return;
109     }
110     int mid=(l+r)>>1;
111     if(x<=mid) update(l,mid,x,v,p<<1);
112      else update(mid+1,r,x,v,p<<1|1);
113     pushup(p);
114 }
115     
116 int querymax(int l,int r,int x,int y,int p)
117 {
118     if(x<=l&&r<=y) return mx[p];
119     int mid=(l+r)>>1;
120     int ans=-oo;
121     if(x<=mid) ans=max(ans,querymax(l,mid,x,y,p<<1));
122     if(y>mid) ans=max(ans,querymax(mid+1,r,x,y,p<<1|1));
123     return ans;
124 }
125 
126 int querysum(int l,int r,int x,int y,int p)
127 {
128     if(x<=l&&r<=y) return sum[p];
129     int mid=(l+r)>>1;
130     int ans=0;
131     if(x<=mid) ans+=querysum(l,mid,x,y,p<<1);
132     if(y>mid) ans+=querysum(mid+1,r,x,y,p<<1|1);
133     return ans;
134 }
135 
136 int qmax(int x,int y)
137 {
138     int ans=-oo;
139     int f1=top[x];
140     int f2=top[y];
141     while(f1!=f2)
142     {
143         if(dep[f1]<dep[f2])
144         {
145             swap(f1,f2);
146             swap(x,y);
147         }
148         ans=max(ans,querymax(1,n,tid[f1],tid[x],1));
149         x=fa[f1]; 
150         f1=top[x];
151     }
152     if(dep[x]>dep[y]) swap(x,y);
153     ans=max(ans,querymax(1,n,tid[x],tid[y],1));
154     return ans;
155 }
156 
157 int qsum(int x,int y)
158 {
159     int ans=0;
160     int f1=top[x];
161     int f2=top[y];
162     while(f1!=f2)
163     {
164         if(dep[f1]<dep[f2])
165         {
166             swap(f1,f2);
167             swap(x,y);
168         }    
169         ans+=querysum(1,n,tid[f1],tid[x],1);
170         x=fa[f1]; 
171         f1=top[x];
172     }
173     if(dep[x]>dep[y]) swap(x,y);
174     ans+=querysum(1,n,tid[x],tid[y],1);
175     return ans;
176 }
177 
178 int main()
179 {
180     freopen("bzoj1036.in","r",stdin);
181     freopen("bzoj1036.out","w",stdout);
182     scanf("%d",&n); 
183     for(int i=1;i<=n-1;i++)
184     {
185         int x,y;
186         scanf("%d%d",&x,&y);
187         add(x,y);
188         add(y,x);
189     }
190     for(int i=1;i<=n;i++) scanf("%d",&a[i]);
191     
192     cnt=0;
193     dfs1(1);
194     memset(flag,0,sizeof(flag));
195     dfs2(1,1);
196     for(int i=0;i<=N-1;i++) mx[i]=-oo;
197     build(1,n,1);
198     int q;
199     scanf("%d",&q);
200     //q=0; 
201     for(int i=1;i<=q;i++)
202     {
203         int x,y;
204         scanf("%s%d%d",ch,&x,&y);
205         if(ch[0]=='C') update(1,n,tid[x],y,1);
206         if(ch[1]=='M') 
207         {
208             int ans=qmax(x,y);
209             printf("%d\n",ans);
210         }
211         if(ch[1]=='S')
212         {
213             int ans=qsum(x,y);
214             printf("%d\n",ans);
215         }
216     }
217 }
218 
219 
220             
221

 UPD（2018.9.20）：C++ LCT写法

  1 #include<cstdio>
  2 #include<cstring>
  3 #include<string>
  4 #include<cmath>
  5 #include<iostream>
  6 #include<algorithm>
  7 #include<map>
  8 #include<set>
  9 #include<queue>
 10 #include<vector>
 11 using namespace std;
 12 typedef long long ll;
 13 typedef unsigned int uint;
 14 typedef unsigned long long ull;
 15 typedef pair<int,int> PII;
 16 typedef vector<int> VI;
 17 #define fi first
 18 #define se second 
 19 #define MP make_pair
 20 #define N   210000
 21 #define MOD 1000000007
 22 #define eps 1e-8 
 23 #define pi acos(-1)
 24 #define oo 1e9
 25  
 26 char ch[10];
 27 int t[N][2],fa[N],a[N],b[N],q[N],rev[N],n,top;
 28 ll w[N],sum[N],mx[N];
 29  
 30 int read()
 31 { 
 32    int v=0,f=1;
 33    char c=getchar();
 34    while(c<48||57<c) {if(c=='-') f=-1; c=getchar();}
 35    while(48<=c&&c<=57) v=(v<<3)+v+v+c-48,c=getchar();
 36    return v*f;
 37 }
 38  
 39 bool isroot(int x)
 40 {
 41     return t[fa[x]][0]!=x&&t[fa[x]][1]!=x;
 42 }
 43  
 44 void pushup(int x)
 45 {
 46     int l=t[x][0];
 47     int r=t[x][1];
 48     sum[x]=sum[l]+sum[r]+w[x];
 49     mx[x]=max(w[x],max(mx[l],mx[r]));
 50 }
 51  
 52 void pushdown(int x)
 53 {
 54     int l=t[x][0];
 55     int r=t[x][1];
 56     if(rev[x])
 57     {
 58         rev[x]^=1;
 59         rev[l]^=1;
 60         rev[r]^=1;
 61         swap(t[x][0],t[x][1]);
 62     } 
 63 }
 64  
 65 void rotate(int x)
 66 {
 67      int y=fa[x];
 68      int z=fa[y];
 69      int l=(t[y][1]==x);
 70      int r=l^1;
 71      if(!isroot(y)) t[z][t[z][1]==y]=x;
 72      fa[t[x][r]]=y; fa[y]=x; fa[x]=z;
 73      t[y][l]=t[x][r]; t[x][r]=y;
 74      pushup(y);
 75      pushup(x);
 76 }
 77  
 78 void splay(int x)
 79 {
 80     q[++top]=x;
 81     for(int i=x;!isroot(i);i=fa[i]) q[++top]=fa[i];
 82     while(top) pushdown(q[top--]);
 83     while(!isroot(x))
 84     {
 85         int y=fa[x];
 86         int z=fa[y];
 87         if(!isroot(y))
 88         {
 89             if(t[y][0]==x^t[z][0]==y) rotate(x);
 90              else rotate(y);
 91         }
 92         rotate(x);
 93     } 
 94 }
 95  
 96 void access(int x)
 97 {
 98     for(int k=0;x;k=x,x=fa[x])
 99     {
100         splay(x);
101         t[x][1]=k;
102         pushup(x);
103     }
104 }
105  
106 void makeroot(int x)
107 {
108     access(x);
109     splay(x);
110     rev[x]^=1;
111 }
112  
113 void link(int x,int y)
114 {
115     makeroot(x);
116     fa[x]=y;
117 }
118  
119 void split(int x,int y)
120 {
121     makeroot(x);
122     access(y);
123     splay(y);
124 }
125  
126 int main()
127 {
128     //freopen("bzoj1036.in","r",stdin);
129     //freopen("bzoj1036.out","w",stdout);
130     int n;
131     scanf("%d",&n); 
132     mx[0]=-oo;
133     for(int i=1;i<=n-1;i++) scanf("%d%d",&a[i],&b[i]);
134     for(int i=1;i<=n;i++)
135     {
136         scanf("%lld",&w[i]); 
137         mx[i]=sum[i]=w[i];
138     }
139     for(int i=1;i<=n-1;i++) link(a[i],b[i]);
140     int q;
141     scanf("%d",&q);
142     for(int i=1;i<=q;i++)
143     {
144         int x,y;
145         scanf("%s%d%d",ch,&x,&y);
146         if(ch[0]=='C')
147         {
148             splay(x);
149             w[x]=y;
150             pushup(x);
151         }
152         if(ch[1]=='M')
153         {
154             split(x,y);
155             ll ans=mx[y];
156             printf("%lld\n",ans);
157         }
158         if(ch[1]=='S')
159         {
160             split(x,y);
161             ll ans=sum[y];
162             printf("%lld\n",ans);
163         }
164     }
165 }

 

posted on 2016-11-24 20:53  myx12345  阅读(386)  评论(0)  编辑  收藏  举报

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