[POJ1003]Hangover

Time Limit: 1000MS   Memory Limit: 10000K
Total Submissions: 111811   Accepted: 54608

Description

How far can you make a stack of cards overhang a table? If you have one card, you can create a maximum overhang of half a card length. (We're assuming that the cards must be perpendicular to the table.) With two cards you can make the top card overhang the bottom one by half a card length, and the bottom one overhang the table by a third of a card length, for a total maximum overhang of 1/2 + 1/3 = 5/6 card lengths. In general you can make n cards overhang by 1/2 + 1/3 + 1/4 + ... + 1/(n + 1) card lengths, where the top card overhangs the second by 1/2, the second overhangs tha third by 1/3, the third overhangs the fourth by 1/4, etc., and the bottom card overhangs the table by 1/(n + 1). This is illustrated in the figure below.


Input

The input consists of one or more test cases, followed by a line containing the number 0.00 that signals the end of the input. Each test case is a single line containing a positive floating-point number c whose value is at least 0.01 and at most 5.20; c will contain exactly three digits.

Output

For each test case, output the minimum number of cards necessary to achieve an overhang of at least c card lengths. Use the exact output format shown in the examples.

Sample Input

1.00
3.71
0.04
5.19
0.00

Sample Output

3 card(s)
61 card(s)
1 card(s)
273 card(s)

Source

思路

  级数求和

var n,k:real;
procedure main;
var i:longint;
begin
    i:=1;k:=0;
    while k<n do
        begin
            inc(i);
            k:=k+(1/i);
        end;
    writeln(i-1,' card(s)');
end;
begin
    while true do
        begin
            read(n);
            if n=0 then halt;
            main;
        end;
end.
View Code

 

posted on 2015-10-24 20:20  川汉唐  阅读(258)  评论(0编辑  收藏  举报

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