# Maximum number of handshakes in java

## 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. ### 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 ### 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`