poj1064 cable master（最大值问题：二分+贪心）

 1 const
 2   maxn=10000;
 3 var
 4   a:array[1..maxn] of longint;
 5   n,k:longint;
 6   procedure init;
 7     var i:longint; x:real;
 8     begin
 9       assign(input,‘poj1064.in‘); reset(input);
10       readln(n,k);
11       for i:=1 to n do
12         begin
13           readln(x);
14           a[i]:=trunc(x*100);
15         end;
16       close(input);
17     end;
18   function can(x:longint):boolean;
19     var s,i:longint;
20     begin
21       s:=0;
22       for i:=1 to n do
23         s:=s+a[i] div x;
24       exit(s>=k);
25     end;
26   function find:longint;
27     var l,r,mid:longint;
28     begin
29       l:=0; r:=10000000;
30       while l<r do
31         begin
32           mid:=(l+r+1) div 2;
33           if can(mid) then l:=mid   //还可能再加长
34           else r:=mid-1; // 过长无法切割k份，需缩短
35         end;
36       exit(l);
37     end;
38 begin
39   init;
40   writeln(find/100.0:0:2);
41 end.