Checking if a math function is valid

[HardToHandle]

I am given the function {1,2,3,4,5}. I have to receive user input on how many ordered pairs he wants, then verify if the function is valid (values for the x-coordinate have to be between 1 and 5, and an x-coordinate CAN'T be repeated). I know how to loop for and check if the value of X is between 1 and 5, however, I am having trouble checking the string for repeating elements. I wrote the conditional expression for x less than 1 and bigger than 5, but I am stumped on how to write an expression that checks for repeating elements. Can somebody help me with that please? This is what I have so far:

import java.util.Scanner;

public class Functions
{
 public static void main (String args [] )
 {
 Scanner in = new Scanner (System.in);
 
 int []domain = new int [5];
 int [] range = new int [5];
 int orderedPairs = 0;
 boolean function = true;
 
 
 
 
 System.out.println ("Enter the number of ordered pairs please: ");
 orderedPairs = in.nextInt();
 while (orderedPairs < 0 || orderedPairs > 5)
 {
 System.out.println ("This input is invalid. Enter a number between 0 and 5 and try again: ");
 orderedPairs = in.nextInt ();
 }
 
  for (int i = 0; i < orderedPairs; i++)
  {
  
  System.out.println ("Enter the x-coordinate please: ");
  domain [i]= in.nextInt();

  System.out.println ("Enter the y-coordinate please: ");
  range [i] = in.nextInt();
  
  }
  
 
  
  
  for (int i = 0; i < orderedPairs; i++)
  {
  System.out.println ("f(" + domain [i] + "): " + range [i]);
  }
  
  
  for (int i = 0; i < orderedPairs;i++)
 {
  
  if (domain [i] > 5 || domain [i] < 1)
  {
  function = false;
  }
  
  for (int n = i + 1; n < orderedPairs; n++)
  {
  if (domain[i] == domain [n] && range [n] != range [i])
  {
  function = false;
  }
  
  }
  
  

   
  
}



  if (function == false)
  {
  System.out.println ("This is NOT a valid function.");
  }
  else if (function == true)
  {
  System.out.println ("This is a valid function.");
  }
   
 
  
  
  
   
 
 }
 


}

Thanks in advance! :)

[pbrockway2]

You declare domain and range to be double arrays, but they are, in fact, 1-dimensional arrays. It would make more sense to declare them as:

int[] domain = new int[5];
int[] range = new int[5];

As for the duplicates check, after you have checked that a domain value is within the right limits you could then use another for loop to determine whether it is equal to any earlier domain value.

[HardToHandle]

You are absolutely right about having a 1D array, I fixed that. Thanks for the help, I understood what you meant and fixed my code now. Cheers!

[pbrockway2]

You're welcome.