7-CoinFlip.java

// Question
/*
**Little Elephant** was fond of inventing new games. After a lot of research, Little Elephant came to know that most of the animals in the forest were showing less interest to play the multi-player games.Little Elephant had started to invent single player games, and succeeded in inventing the new single player game named **COIN FLIP**. In this game the player will use N coins numbered from 1 to N, and all the coins will be facing in "Same direction" (Either **Head** or **Tail**), which will be decided by the player before starting of the game. The player needs to play N rounds.In thek-th round the player will flip the face of the all coins whose number is less than or equal tok. That is, the face of coini will be reversed, from **Head** to **Tail**, or, from **Tail** to **Head**, for i≤k. Elephant needs to guess the total number of coins showing a particular face after playing N rounds. Elephant really becomes quite fond of this game **COIN FLIP** so Elephant plays G times. Please help the Elephant to find out the answer. ### Input: - The first line of input contains an integer T, denoting the number of test cases. Then T test cases follow. - The first line of each test contains an integer G, denoting the number of games played by Elephant. Each of the following G lines denotes a single game, and contains 3 space-separated integers I, N, Q, where I denotes the initial state of the coins, N denotes the number of coins and rounds, and Q, which is either 1, or 2 as explained below. Here I=1 means all coins are showing **Head** in the start of the game, and I=2 means all coins are showing **Tail** in the start of the game. Q=1 means Elephant needs to guess the total number of coins showing **Head** in the end of the game, and Q=2 means Elephant needs to guess the total number of coins showing Tail in the end of the game. ### Output: For each game, output one integer denoting the total number of coins showing the particular face in the end of the game. ### Constraints: - 1≤T≤10 - 1 ≤ G ≤ 20000
- 1 ≤ N ≤ 109
- 1 ≤ I ≤ 2
- 1 ≤ Q ≤ 2
### Sample Input: ``` 1 2 1 5 1 1 5 2 ``` ### Sample Output: ``` 2 3 ``` ### Explanation: - In the 1st game in Example, I=1, so initial arrangement of coins are H H H H H, and now Elephant will play 5 rounds and coin faces will be changed as follows
After the 1st Round: T H H H H
After the 2nd Round: H T H H H
After the 3rd Round: T H T H H
After the 4th Round: H T H T H
After the 5th Round: T H T H T
Finally Q=1, so we need to find the total number of coins showing Head, which is 2.

In the 2nd game in Example: This is similar to the 1st game, except Elephant needs to find the total number of coins showing **Tail**. So the Answer is 3. (Please see the final state of the coins in the 1 st game)
*/


// Solution

/* package codechef; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

class sol
{
	public static void main (String[] args) throws java.lang.Exception
	{
		Scanner scan=new Scanner(System.in);
		int test=scan.nextInt();
		while(test-->0){
		    int noOfGames=scan.nextInt();
		    while(noOfGames-->0){
		        int initial=scan.nextInt();
		        int rounds=scan.nextInt();
		        int count=scan.nextInt();
		        int heads=0; int tails =0;
		        if((rounds&1)==0){
		            heads=rounds/2; tails=rounds/2;
		            }else{
		        if(initial==1){
		                tails = rounds/2 + 1;
		                heads = rounds/2;
		        }
		        else if(initial==2){
		            heads = rounds/2 + 1;
		                tails = rounds/2;
		        }
		        else {System.out.println("Enter either 1 or 2");}
		            }
		        if(count==1){
		            System.out.println(heads);
		        }
		        else{
		            System.out.println(tails);
		        }
		    }
		}
	}
}