算法模板——左偏树（可并堆）

 1 var
 2    i,j,k,l,m,n,head:longint;
 3    a,lef,rig,fix:array[0..100000] of longint;
 4 function min(x,y:longint):longint;inline;
 5          begin
 6               if x<y then min:=x else min:=y;
 7          end;
 8 function max(x,y:longint):longint;inline;
 9          begin
10               if x>y then max:=x else max:=y;
11          end;
12 procedure swap(var x,y:longint);inline;
13           var z:longint;
14           begin
15                z:=x;x:=y;y:=z;
16           end;
17 procedure merge(var x,y:longint);
18           begin
19                if x=0 then swap(x,y);
20                if y=0 then exit;
21                if a[x]>a[y] then swap(x,y);
22                merge(rig[x],y);
23                fix[x]:=min(fix[lef[x]],fix[rig[x]])+1;
24                if fix[lef[x]]<fix[rig[x]] then swap(lef[x],rig[x]);
25           end;
26 function cuthead(var x:longint):longint;
27          var a1:longint;
28           begin
29                a1:=a[x];
30                merge(lef[x],rig[x]);
31                x:=lef[x];
32                exit(a1);
33           end;
34 begin
35      readln(n);m:=0;head:=0;
36      for i:=1 to n do
37          begin
38               read(j);
39               case j of
40                    1:begin
41                           readln(k);
42                           inc(m);a[m]:=k;l:=m;
43                           merge(head,l);
44                    end;
45                    2:begin
46                           readln;
47                           writeln(cuthead(head));
48                    end;
49               end;
50          end;
51 end.
52