NOIP2009T2 分数线划定

 

 

const
    maxN=5010;
var
    n,m,i,j,ans1,ans2:longint;
    a:array[1..maxN,1..2] of longint;
procedure qsort(l,r:longint);
var i,j,mid,t,mid1:longint;
begin
    i:=l;j:=r;mid:=a[(l+r) div 2,2];mid1:=a[(l+r) div 2,1];
    repeat
        while (a[i,2]>mid)or((a[i,2]=mid)and(a[i,1]<mid1)) do inc(i);
        while (a[j,2]<mid)or((a[j,2]=mid)and(a[j,1]>mid1)) do dec(j);
        if i<=j then
        begin
            a[maxN]:=a[i]; a[i]:=a[j]; a[j]:=a[maxN];
            inc(i);dec(j);
        end;
    until i>j;
    if i<r then qsort(i,r);
    if j>l then qsort(l,j);
end;

begin
    assign(input,'score.in'); reset(input);
    assign(output,'score.out'); rewrite(output);
    readln(n,m);
    for i:=1 to n do readln(a[i,1],a[i,2]);
    qsort(1,n);
    m:=trunc(m*1.5);
    while a[m,2]=a[m+1,2] do inc(m);
    writeln(a[m,2],' ',m);
    for i:=1 to m do writeln(a[i,1],' ',a[i,2]);
end.