title: Check Whether Arithmetic Progression Can Formed Given Array
signature: class Solution {
  
      public Boolean checkWhetherArithmeticProgressionCanFormedGivenArray(ArrayList<Integer> arr, Integer n) {
test_code: import static java.util.Map.entry;  
  import java.util.*;
  import java.lang.*;
  // TESTING CODE 
  // ============================================
  class QuestionEvaluator {
      public static String validateSolution(ArrayList<Integer> arr, Integer n, Boolean expected){
          try{
              Driver driver = new Driver();
              if (driver.run(arr, n,expected)){
                  return "PASSED";
              }
              return "FAILED";
              
          } catch (Exception exception_obj){
              return exception_obj.getClass().getSimpleName();
          }
  
      }
      public static void main(String[] args) {
          String result;
          result = validateSolution(new ArrayList<>(Arrays.asList(1, 4, 16, 64)), 4, false);
          System.out.println(String.format("%s%s","TEST-0...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(0, 4, 8, 12)), 4, true);
          System.out.println(String.format("%s%s","TEST-1...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(-2, 0, 2, 4, 6)), 5, true);
          System.out.println(String.format("%s%s","TEST-2...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)), 7, true);
          System.out.println(String.format("%s%s","TEST-3...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(46, 56, 66, 76, 86)), 5, true);
          System.out.println(String.format("%s%s","TEST-4...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(46, 56, 56, 66, 76, 86)), 6, false);
          System.out.println(String.format("%s%s","TEST-5...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(7, 9, 11, 21, 44, 45, 61, 67, 78, 97, 98, 99)), 11, false);
          System.out.println(String.format("%s%s","TEST-6...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(-96, -84, -74, -70, -68, -62, -50, -50, -38, -36, -36, -36, -34, -34, -28, -28, -26, -18, -12, -4, -4, -2, -2, 6, 6, 14, 24, 34, 36, 44, 50, 54, 54, 62, 64, 66, 70, 74, 74, 78, 84, 86)), 33, false);
          System.out.println(String.format("%s%s","TEST-7...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1)), 33, false);
          System.out.println(String.format("%s%s","TEST-8...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(1, 3, 5, 11, 14, 15, 15, 17, 18, 19, 20, 20, 22, 32, 33, 35, 36, 37, 39, 44, 45, 46, 51, 54, 57, 58, 61, 61, 63, 64, 67, 69, 70, 70, 79, 82, 86, 89, 92, 93, 95, 99)), 40, false);
          System.out.println(String.format("%s%s","TEST-9...",result));    
      
      }
  }
  
  class Driver{
      public boolean run(ArrayList<Integer> arr, Integer n, Boolean expected){
  
          PLACEHOLDER_CLS_NAME sol = new PLACEHOLDER_CLS_NAME();
          return validateSolution(sol.PLACEHOLDER_FN_NAME(arr, n),expected);
      }
      
      public boolean validateSolution(Boolean actual, Boolean expected){
          return actual.equals(expected);
      }
  }
  
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
source_py: def check_whether_arithmetic_progression_can_formed_given_array(arr, n):
      if (n == 1):
          return True
      arr.sort()
      d = (arr[1] - arr[0])
      for i in range(2, n):
          if ((arr[i] - arr[(i - 1)]) != d):
              return False
      return True
source_cpp: bool check_whether_arithmetic_progression_can_formed_given_array(vector<int> arr, int n) {
    if ( n == 1 ) return true;
    sort(arr.begin(), arr.end());
    int d = arr [ 1 ] - arr [ 0 ];
    for ( int i = 2;
    i < n;
    i ++ ) if ( arr [ i ] - arr [ i - 1 ] != d ) return false;
    return true;
  }