POJ 1003

Hangover

Time Limit: 1000MS		Memory Limit: 10000K
Total Submissions: 88848		Accepted: 42920

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
Mid-Central USA 2001

题目翻译：
你能让一堆卡片悬出桌子多远？如果你有一张卡片，你最多能让它悬出它自身一半的长度（假设卡片对于桌子是垂直的//= =这是为毛。。）。两张卡的话，你就只能悬出在上面那张卡的一半长度，下面那张卡三分之一长度，总的长度就是1/3+1/2=5/6.。。（可以通过计算得出这个结论）。 以此类推的话，你就能得到n张牌能排多长的结论：
1/2 + 1/3 + 1/4 + ...
+ 1/(n + 1) 如图；

输入：包含一组或多组数据。最小0.01最大5.20
输出：对于每一组测试数据，输出达到给出的长度所需的最小卡牌数值。

分析：就是给你个数c，让你求1/2 + 1/3 + 1/4
+ ... + 1/(n + 1) 中大于等于c最小的n值
C++代码：

#include <iostream>
using namespace std;
int main()
{
double c;
while(cin>>c)
{
if(c==0.00) break;
double sum=0;
double n;
for(n=1;;n++)
{
//double sum=0;
sum+=1/(n+1);
if(!(sum<c))
{
break;
}
}
cout<<n<<" card(s)"<<endl;
}
}

总结：1、一个就是double的问题了= = int 除法一下子全成0了
2、还有一个是，看大神们的报告全都有打表。。。我还在怀疑自己的程序能不能过时间，没想到过了，但是= =打表是什么！！！！！？？