陈启峰 Size Balanced Tree （程序）

program CQF_SBT;const maxn=2000000;var key,s,left,right,a,b:array[0..maxn] of longint; tt,q:longint;procedure init;begin readln(q); for q:=1 to q do readln(a[q],b[q]);end;procedure work;var t,k:longint;procedure right_rotate(var t:longint);inline;begin k:=left[t]; left[t]:=right[k]; right[k]:=t; s[k]:=s[t]; s[t]:=s[left[t]]+s[right[t]]+1; t:=k;end;procedure left_rotate(var t:longint);inline;begin k:=right[t]; right[t]:=left[k]; left[k]:=t; s[k]:=s[t]; s[t]:=s[left[t]]+s[right[t]]+1; t:=k;end;procedure maintain(var t:longint;flag:boolean);inline;begin if flag=false then if s[left[left[t]]]>s[right[t]] then right_rotate(t) else if s[right[left[t]]]>s[right[t]] then begin left_rotate(left[t]); right_rotate(t); end else exit else if s[right[right[t]]]>s[left[t]] then left_rotate(t) else if s[left[right[t]]]>s[left[t]] then begin right_rotate(right[t]); left_rotate(t); end else exit; maintain(left[t],false); maintain(right[t],true); maintain(t,true); maintain(t,false);end;procedure insert(var t,v:longint);inline;begin if t=0 then begin inc(tt); t:=tt; key[t]:=v; s[t]:=1; left[t]:=0; right[t]:=0; end else begin inc(s[t]); if v<key[t] then insert(left[t],v) else insert(right[t],v); maintain(t,v>=key[t]); end;end;function delete(var t:longint;v:longint):longint;inline;begin dec(s[t]); if (v=key[t])or(v<key[t])and(left[t]=0)or(v>key[t])and(right[t]=0) then begin delete:=key[t]; if (left[t]=0)or(right[t]=0) then t:=left[t]+right[t] else key[t]:=delete(left[t],key[t]+1); end else if v<key[t] then delete:=delete(left[t],v) else delete:=delete(right[t],v);end;function find(var t,v:longint):boolean;inline;begin if t=0 then exit(false); if v<key[t] then find:=find(left[t],v) else find:=(key[t]=v)or find(right[t],v);end;function rank(var t,v:longint):longint;inline;begin if t=0 then exit(1); if v<=key[t] then rank:=rank(left[t],v) else rank:=s[left[t]]+1+rank(right[t],v);end;function select(var t:longint;k:longint):longint;inline;begin if k=s[left[t]]+1 then exit(key[t]); if k<=s[left[t]] then select:=select(left[t],k) else select:=select(right[t],k-1-s[left[t]]);end;function pred(var t,v:longint):longint;inline;begin if t=0 then exit(v); if v<=key[t] then pred:=pred(left[t],v) else begin pred:=pred(right[t],v); if pred=v then pred:=key[t]; end;end;function succ(var t,v:longint):longint;inline;begin if t=0 then exit(v); if key[t]<=v then succ:=succ(right[t],v) else begin succ:=succ(left[t],v); if succ=v then succ:=key[t]; end;end;begin tt:=0; t:=0; s[0]:=0; for q:=1 to q do case a[q] of 1:insert(t,b[q]); 2:delete(t,b[q]); 3:writeln(find(t,b[q])); 4:writeln(rank(t,b[q])); 5:writeln(select(t,b[q])); 6:writeln(pred(t,b[q])); 7:writeln(succ(t,b[q])); end;end;begin assign(input,'bst.in'); assign(output,'bst.out'); reset(input); rewrite(output); init; work; close(input); close(output);end.