Description
Get the number of people in the room as input from the user. Then calculate the maximum number of handshakes possible among that people.
For e.g.
If there are N people in the room then the first person has to shake hand with N-1 people and second person has to shake hand with N-1-1 people i.e., N-2 handshakes are possible. Thus, it goes on.
So total hand shakes = N-1 + N-2 + N-3 +………+1 + 0
Input
10
Output
45
C Program
#include <stdio.h>
int main()
{
int num;
printf("Enter the number of people in the room: ");
scanf("%d",&num);
int total = num * (num-1) / 2;
printf("Total handshakes = %d",total);
return 0;
}
C++ Program
#include <iostream>
using namespace std;
int main()
{
int num;
cout<<"Enter the number of people in the room: ";
cin>>num;
int total = num * (num-1) / 2;
cout<<"Total handshakes = "<<total;
return 0;
}
Java
import java.util.Scanner;
public class Main
{
public static void main(String[] args) {
Scanner sc=new Scanner(System.in);
System.out.print("Enter the number of people in the room: ");
int num = sc.nextInt();
int total = num * (num-1) / 2;
System.out.println("Total number of handshakes = "+total);
}
}
Python
num= int(input("Enter the number of people in the room: "))
total = int(num * ((num - 1) / 2))
print("Total number of handshakes = ",total)