13、Hangover

最新推荐文章于 2025-09-07 20:32:33 发布

转载最新推荐文章于 2025-09-07 20:32:33 发布 · 81 阅读

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原文链接：http://www.cnblogs.com/langzi1996/p/6629547.html

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#java

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)

解题思路：刚开始看这道题，图文并茂还以为很难，结果是一道水题。不过既然做了就写一下：用了一个递归求n块板子的总悬挂长度，然后在主函数中比较输入长度和n块板子的总悬挂长度（n从1开始），当输入长度刚好小于或等于n块板子的悬挂长度时，按格式输出此时的n。

具体代码：

 1 import java.util.*;
 2 public class Main {
 3      public static float totalLength(int n){
 4           if(n==1)
 5               return (float)1/2;
 6           return (float)1/(n+1)+totalLength(n-1);
 7      }
 8 
 9      public static void main(String[] args) {
10           Scanner scanner=new Scanner(System.in);
11           float temp;
12           int i;
13           while((temp=scanner.nextFloat())!=0.00f){
14               for(i=1;temp>totalLength(i);i++);
15               System.out.println(i+" card(s)");
16           }
17      }
18 }