POJ 3994：Probability One

Probability One

Time Limit: 1000MS		Memory Limit: 65536K
Total Submissions: 1674		Accepted: 1151

Description

Number guessing is a popular game between elementary-school kids. Teachers encourage pupils to play the game as it enhances their arithmetic skills, logical thinking, and following-up simple procedures. We think that, most probably, you too will master in few minutes. Here’s one example of how you too can play this game: Ask a friend to think of a number, let’s call it n₀. Then: 

1. Ask your friend to compute n₁ = 3 * n₀ and to tell you if n₁ is even or odd.
   
2. If n₁ is even, ask your friend to compute n₂ = n₁/2. If, otherwise, n₁ was odd then let your friend compute n₂ = (n₁ + 1)/2.
   
3. Now ask your friend to calculate n₃ = 3 * n₂.
   
4. Ask your friend to tell tell you the result of n₄ = n₃/9. (n₄ is the quotient of the division operation. In computer lingo, ’/’ is the integer-division operator.)
   
5. Now you can simply reveal the original number by calculating n₀ = 2 * n₄ if n₁ was even, or n₀ = 2 * n₄ + 1 otherwise.
   

Here’s an example that you can follow: If n₀ = 37, then n₁ = 111 which is odd. Now we can calculate n₂ = 56, n₃ = 168, and n₄ = 18, which is what your friend will tell you. Doing the calculation 2 * n₄ + 1 = 37 reveals n₀.

Input

Your program will be tested on one or more test cases. Each test case is made of a single positive number (0 < n₀ < 1,000,000). 
The last line of the input file has a single zero (which is not part of the test cases.)

Output

For each test case, print the following line: 
k. B Q 
Where k is the test case number (starting at one,) B is either ’even’ or ’odd’ (without the quotes) depending on your friend’s answer in step 1. Q is your friend’s answer to step 4.

Sample Input

37
38
0

Sample Output

1. odd 18
2. even 19

把整个过程换算完了就是把原数除以2。

代码：

#include <iostream>
#include <algorithm>
#include <cmath>
#include <vector>
#include <string>
#include <cstring>
using namespace std;

int main()
{
	int num,i=1;
	while(cin>>num)
	{
		if(num==0)
			break;
		cout<<i<<". ";
		i++;
		if(num%2)
			cout<<"odd ";
		else
			cout<<"even ";
		cout<<num/2<<endl;
	}
	return 0;
}

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