最小生成树kruscal+并查集

program as;type  t1     =record  x,y,h  :longint;end;var  n,m,s,i:longint;  a      :array[1..1000000] of t1;  f      :array[0..1000000] of longint;  bool   :array[1..1000,1..1000] of boolean;  sum    :longint;  totel  :longint;function find(x:longint):longint;begin  if x<>f[x] then    begin      f[x]:=find(f[x]);      exit(f[x]);    end  else  exit(x);end;procedure kuai(l,r:longint);var  i,j,x     :longint;  y         :t1;begin  i:=l; j:=r;  x:=a[(l+r) div 2].h;  repeat    while a[i].h<x do inc(i);    while a[j].h>x do dec(j);    if i<=j then      begin        y:=a[i];        a[i]:=a[j];        a[j]:=y;        inc(i);        dec(j);      end;  until i>j;  if i<r then kuai(i,r);  if l<j then kuai(l,j);end;procedure duru;var  i,j,x1  :longint;begin  read(n);  s:=0;  fillchar(a,sizeof(a),0);  fillchar(bool,sizeof(bool),true);  for i:=1 to n do    for j:=1 to n do     begin       read(x1);       if (i<>j)and(bool[i,j]) then       begin         inc(s);         a[s].x:=i;         a[s].y:=j;         a[s].h:=x1;         bool[i,j]:=false;         bool[j,i]:=false;       end;     end;end;procedure kruscal;var  x,y,i,j :longint;begin  for i:=1 to s do    f[i]:=i;  for i:=1 to s do    begin      x:=find(a[i].x);      y:=find(a[i].y);      if x<>y then        begin          f[x]:=y;          inc(sum,a[i].h);          inc(totel);        end;      if totel=n-1 then        exit;    end;end;begin  duru;  kuai(1,s);  kruscal;  writeln(sum);end.