C :

#include <stdio.h>
#include <stdlib.h>
int main()
{
	int a[6];
	scanf("%d%d%d",&a[0],&a[1],&a[2]);
	if(a[2]-a[1]==a[1]-a[0])
	{
		int i;
		for(i=3;i<6;i++)
			a[i]=a[i-1]+a[2]-a[1];
	}
	else if(a[2]/a[1]==a[1]/a[0])
	{
		int i;
		for(i=3;i<6;i++)
			a[i]=a[i-1]*(a[2]/a[1]);
	}
	printf("%d %d %d\n",a[3],a[4],a[5]);
	return 0;
}
//Author: ITProgrammer

C++ :

#include<iostream>
using namespace std;
int main(){ 
   int a,b,c;
   cin>>a>>b>>c;
   if(c - b == b - a){ 
      int t = c - b;
      cout<<c + t <<" " <<c + 2 * t <<" " << c + 3 * t<<endl;
   }else{ 
      int t = c / b;
      cout<<c * t <<" " <<c * t * t <<" " << c * t * t * t<<endl;
   }
   return 0;
}

Pascal :

var
  a,b,c:longint;
begin
  read(a,b,c);
  if(a*2=b) and (b*2=c) then write(c*2,' ',c*4,' ',c*8);
  if(b-a=c-b)then write(c+b-a,' ',c+(b-a)*2,' ',c+(b-a)*3);
end.

Java :

import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		String str=new Scanner(System.in).nextLine();
		String[] strArray=str.split(" ");
		int a1=Integer.valueOf(strArray[0]);
		int a2=Integer.valueOf(strArray[1]);
		int a3=Integer.valueOf(strArray[2]);
		boolean isDb=false;
		boolean isDc=false;
		isDb=isDb(a1,a2,a3);
		isDc=isDc(a1,a2,a3);
		int a4,a5,a6;
		if(isDb){
			a4=(int)((float)a3/(float)a2)*a3;
			a5=(int)((float)a4/(float)a3)*a4;
			a6=(int)((float)a5/(float)a4)*a5;
		}else{
			a4=a3-a2+a3;
			a5=a4-a3+a4;
			a6=a5-a4+a5;
		}
		System.out.println(a4+" "+a5+" "+a6);
	}
	public static boolean isDc(int a,int b,int c){
		boolean f=true;
		if(b-a==c-b){
			f=true;
		}else{
			f=false;
		}
		return f;
	}
	
	public static boolean isDb(int a,int b,int c){
		boolean f=true;
		if((double)b/(double)a==(double)c/(double)b){
			f=true;
		}else{
			f=false;
		}
		return f;
	}

}

Python :

a,b,c=map(int,input().split())
if c-b==b-a:
    t=c-b
    print(c+t,c+t+t,c+t+t+t)
else:
    t=c//b
    print(c*t,c*t*t,c*t*t*t)