Maximum number of handshakes in java

September 30, 2022

Maximum number of handshakes in Java

Here, we will discuss the maximum number of handshakes in java. The given program will find the maximum number of handshakes in a room. Suppose there are N persons in a room. We have to find the maximum number of Handshakes possible. Given the fact that any two persons shake hand only once.

MAximum number of handshakes in Java

Approach :

For the number of handshakes to be maximum, every person should hand-shake with every other person in the room

i.e. all persons present should shake hands.

  • For the first person, there will be N-1 people to shake hands with
  • For second person, there will be N -1 people available but as he has already shaken hands with the first person, there will be N-1-1 = N-2 shake-hands
  • For third person, there will be N-1-1-1 = N-3, and So On…

Therefore the total number of handshake   =   ( N – 1 + N – 2 +….+ 1 + 0 )   =   ( (N-1) * N ) / 2.

Algorithm

  • For N = 8
  • handshakes  =  ( (N-1) * N ) / 2  =  ( 8 x 7 )/2  =  28
  • Print Result
 
 

Addition of two fractions

Replace all 0’s with 1 in a given integer

Can a number be expressed as a sum of two prime numbers

java program for finding the maximum number of handshakes

Java Code

Run 
public class Main
{
	public static void main(String[] args) {
	     //fill the code
    int num = 10;

    int total = num * (num-1) / 2; // Combination nC2

		System.out.println("For "+ num +" people there will be " +total+" handshakes");
	}
}

Output

Maximum number of handshakes for 30 people are 435

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3 comments on “Maximum number of handshakes in java”


  • 4007

    public class Main {
    public static void main(String[] args) {
    Scanner scan=new Scanner(System.in);
    int f=scan.nextInt();
    int y=f*(f-1);
    System.out.println(y/2);
    }
    }


  • Pulivendula

    import java.util.*;
    public class Main
    {
    public static void main(String[] args)
    {
    Scanner s = new Scanner(System.in);

    int n=5; int r=9;
    int f=1;
    for(int i=1; i<=n; i++)
    {
    f=f*i;
    }

    int n1=n-r;
    int f1=1;

    for(int j=1; j<=n1; j++)
    {
    f1=f1*j;
    }

    int p=f/f1;
    System.out.println(p);

    }
    }