bzoj 1208 宠物收养所

这个题也是单点维护，不管来的是人还是狗，只要num=0就插入，否则就删除，想清楚了就很好写。
Pets
  1 const
  2     maxn=100000;
  3     ms=1000000;
  4 var
  5     c:array[0..maxn,0..1]of longint;
  6     size,fa,key:array[0..maxn]of longint;
  7     i,n,a,b,tot,sum,num,now,ans,tmp,rot:longint;
  8 procedure update(x:longint);
  9 begin
 10     size[x]:=size[c[x,0]]+size[c[x,1]]+1;
 11 end;
 12 
 13 procedure rotate(var rot:longint; x:longint);
 14 var
 15     y,z,p,q:longint;
 16 begin
 17     y:=fa[x]; z:=fa[y];
 18     if c[y,0]=x then p:=0 else p:=1;
 19     q:=p xor 1;
 20     if y=rot then rot:=x
 21     else
 22     if y=c[z,0] then c[z,0]:=x else c[z,1]:=x;
 23     fa[x]:=z; fa[y]:=x; fa[c[x,q]]:=y;
 24     c[y,p]:=c[x,q]; c[x,q]:=y;
 25     update(y); update(x);
 26 end;
 27 
 28 procedure splay(var rot:longint; x:longint);
 29 var
 30     y,z:longint;
 31 begin
 32     while x<>rot do
 33         begin
 34             y:=fa[x]; z:=fa[y];
 35             if y<>rot then
 36                 if (c[y,0]=x)xor(c[z,0]=y) then
 37                     rotate(rot,x)
 38                 else rotate(rot,y);
 39             rotate(rot,x);
 40         end;
 41 end;
 42 
 43 procedure find(t,x:longint);
 44 begin
 45     if t=0 then exit;
 46     if ( abs(key[t]-x)<abs(key[tmp]-x) )
 47         or ( (abs(key[t]-x)=abs(key[tmp]-x))and(key[tmp]>key[t]) ) then
 48         tmp:=t;
 49     if (x<key[t])and(c[t,0]<>0) then find(c[t,0],x)
 50     else
 51     if (x>key[t])and(c[t,1]<>0) then find(c[t,1],x);
 52 end;
 53 
 54 function getmax(x:longint):longint;
 55 begin
 56     if c[x,1]=0 then exit(x) else exit(getmax(c[x,1]));
 57 end;
 58 
 59 procedure insert(var t:longint;x,anc:longint);
 60 begin
 61     if t=0 then
 62         begin
 63             inc(num);
 64             t:=num;
 65             c[t,0]:=0;c[t,1]:=0;
 66             key[t]:=x;
 67             fa[t]:=anc;
 68             splay(rot,t);
 69         end
 70     else
 71         if x<key[t] then insert(c[t,0],x,t)
 72         else
 73         if x>key[t] then insert(c[t,1],x,t);
 74 end;
 75 
 76 procedure delete(var t:longint);
 77 var
 78     p:longint;
 79 begin
 80     if (c[t,0]=0)and(c[t,1]=0) then t:=0
 81     else
 82     if (c[t,0]<>0)and(c[t,1]=0) then
 83         begin
 84             fa[c[t,0]]:=0;
 85             t:=c[t,0];
 86         end
 87     else
 88     if (c[t,1]<>0)and(c[t,0]=0) then
 89         begin
 90             fa[c[t,1]]:=0;
 91             t:=c[t,1];
 92         end
 93     else
 94         begin
 95             p:=getmax(c[t,0]);
 96             splay(c[t,0],p);
 97             c[p,1]:=c[t,1];
 98             fa[c[t,1]]:=p;
 99             fa[p]:=0;
100             c[t,0]:=0; c[t,1]:=0; fa[t]:=0;
101             t:=p;
102         end;
103 end;
104 
105 begin
106     readln(n);
107     for i:=1 to n do
108         begin
109             readln(a,b);
110             if (sum=0)or(a=now) then
111                 begin
112                     insert(rot,b,0);
113                     inc(sum);
114                     now:=a;
115                 end
116             else
117                 begin
118                     tmp:=rot;
119                     find(rot,b);
120                     ans:=(ans+abs(key[tmp]-b)) mod ms;
121                     splay(rot,tmp);
122                     delete(rot);
123                     dec(sum);
124                 end;
125         end;
126     writeln(ans);
127 end.
posted @ 2013-03-28 19:19 Zig_zag 阅读(230) 评论(0) 编辑收藏举报
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