bzoj1098 1301

这两题很类似，都是在补图上搜索

但是由于补图太大我们不能建出来

考虑先从一个点搜，每次搜可以搜的点，

然后维护一个链表，记录当前还没有搜过的点，搜过之后从链表中删除即可

 type node=record
        po,next:longint;
      end;

 var e:array[..] of node;
     l:array[..] of node;
     p,q,ans:array[..] of longint;
     can,v:array[..] of boolean;
     s,i,n,m,len,x,y:longint;

 procedure add(x,y:longint);
   begin
     inc(len);
     e[len].po:=y;
     e[len].next:=p[x];
     p[x]:=len;
   end;

 procedure swap(var a,b:longint);
   var c:longint;
   begin
     c:=a;
     a:=b;
     b:=c;
   end;

 procedure sort(l,r:longint);
   var i,j,x:longint;
   begin
     i:=l;
     j:=r;
     x:=ans[(l+r) shr ];
     repeat
       while ans[i]<x do inc(i);
       while x<ans[j] do dec(j);
       if not(i>j) then
       begin
         swap(ans[i],ans[j]);
         inc(i);
         dec(j);
       end;
     until i>j;
     if l<j then sort(l,j);
     if i<r then sort(i,r);
   end;

 procedure del(i:longint);
   begin
     l[l[i].po].next:=l[i].next;
     if l[i].next<>- then l[l[i].next].po:=l[i].po;
   end;

 procedure bfs;
   var f,r,i,t:longint;
   begin
     while l[].next<>- do
     begin
       f:=;
       r:=;
       v[l[].next]:=true;
       q[]:=l[].next;
       del(l[].next);
       t:=;
       while f<=r do
       begin
         x:=q[f];
         i:=p[x];
         while i<> do
         begin
           can[e[i].po]:=true;
           i:=e[i].next;
         end;
         i:=l[].next;
         while i>- do
         begin
           if not v[i] and not can[i] then
           begin
             inc(r);
             q[r]:=i;
             del(i);
             inc(t);
             v[i]:=true;
           end;
           i:=l[i].next;
         end;
         i:=p[x];
         while i<> do
         begin
           can[e[i].po]:=false;
           i:=e[i].next;
         end;
         inc(f);
       end;
       inc(s);
       ans[s]:=t;
     end;
   end;

 begin
   readln(n,m);
   for i:= to m do
   begin
     readln(x,y);
     add(x,y);
     add(y,x);
   end;
   for i:= to n do
   begin
     l[i].po:=i-;
     l[i-].next:=i;
   end;
   l[n].next:=-;
   bfs;
   sort(,s);
   writeln(s);
   for i:= to s do
     write(ans[i],' ');
   writeln;
 end.

1098

 type node=record
        po,next:longint;
      end;

 var e:array[..] of node;
     l:array[..] of node;
     p:array[..] of longint;
     can:array[..] of boolean;
     i,n,m,x,y,len:longint;

 procedure add(x,y:longint);
   begin
     inc(len);
     e[len].po:=y;
     e[len].next:=p[x];
     p[x]:=len;
   end;

 procedure del(i:longint);
   begin
     l[l[i].po].next:=l[i].next;
     if l[i].next<>- then l[l[i].next].po:=l[i].po;
   end;

 procedure dfs(x:longint);
   var i,j:longint;
   begin
     writeln(x);
     del(x);
     i:=p[x];
     while i<> do
     begin
       can[e[i].po]:=true;
       i:=e[i].next;
     end;
     i:=l[].next;
     while i>- do
     begin
       if not can[i] then
       begin
         j:=p[x];
         while j<> do
         begin
           can[e[j].po]:=false;
           j:=e[j].next;
         end;
         dfs(i);
         exit;
       end;
       i:=l[i].next;
     end;
   end;

 begin
   readln(n,m);
   for i:= to m do
   begin
     readln(x,y);
     add(x,y);
     add(y,x);
   end;
   for i:= to n do
   begin
     l[i-].next:=i;
     l[i].po:=i-;
   end;
   l[n].next:=-;
   dfs();
 end.

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