title: Binary Search
signature: class Solution {
  
      public Integer binarySearch(ArrayList<Integer> arr, Integer l, Integer r, Integer x) {
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 l, Integer r, Integer x, Integer expected){
          try{
              Driver driver = new Driver();
              if (driver.run(arr, l, r, x,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(3, 4, 4, 8, 9, 13, 13, 15, 18, 27, 30, 32, 42, 48, 50, 52, 56, 66, 69, 69, 77, 84, 84, 93)), 19, 12, 22, -1);
          System.out.println(String.format("%s%s","TEST-0...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(52, -58, -22, -80, 44, -52, -34, 94, -34, -74, 42, 60, -62, 70, 98, 32, 10, 94, 26, 56, -48, -50, 42, 2, 46, 28, -68, -16, -96, -12, 66, -46, 74, -60, -52, 28, -92, -78, 32, 28, 16, 34, 30, -60, -14)), 40, 35, 44, -1);
          System.out.println(String.format("%s%s","TEST-1...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(0, 1)), 1, 1, 1, 1);
          System.out.println(String.format("%s%s","TEST-2...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(28, 84, 40, 81)), 2, 2, 2, -1);
          System.out.println(String.format("%s%s","TEST-3...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(-66, -62, -60, -56, -56, -2, 40, 44, 50, 74, 82, 94)), 8, 6, 8, -1);
          System.out.println(String.format("%s%s","TEST-4...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(1, 0, 0, 0, 0, 1, 0, 1, 0, 1, 1)), 7, 7, 10, -1);
          System.out.println(String.format("%s%s","TEST-5...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(15, 26, 31, 36, 36, 61, 68, 72, 75, 79, 82, 98)), 6, 7, 8, -1);
          System.out.println(String.format("%s%s","TEST-6...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(0, -82, -94, 48, 48, -96, 14, 66, 76, -30, 86, 28, -28, -66, -64, 92, -94, -66, 86, 26, 8, 94, -82, -80, 4, -26, 76, -46, 72, 88, -6, 8, -30, 40, -88, 2, -40, -98, -22, -20, 4, -12, 54, -20, -36, 12)), 38, 33, 39, -1);
          System.out.println(String.format("%s%s","TEST-7...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1)), 12, 10, 6, -1);
          System.out.println(String.format("%s%s","TEST-8...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(81, 47)), 1, 1, 1, -1);
          System.out.println(String.format("%s%s","TEST-9...",result));    
      
      }
  }
  
  class Driver{
      public boolean run(ArrayList<Integer> arr, Integer l, Integer r, Integer x, Integer expected){
  
          PLACEHOLDER_CLS_NAME sol = new PLACEHOLDER_CLS_NAME();
          return validateSolution(sol.PLACEHOLDER_FN_NAME(arr, l, r, x),expected);
      }
      
      public boolean validateSolution(Integer actual, Integer expected){
          return actual.equals(expected);
      }
  }
  
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
source_py: def binary_search(arr, l, r, x):
      if (r >= l):
          mid = (l + ((r - l) // 2))
          if (arr[mid] == x):
              return mid
          elif (arr[mid] > x):
              return binary_search(arr, l, (mid - 1), x)
          else:
              return binary_search(arr, (mid + 1), r, x)
      else:
          return (- 1)
source_cpp: int binary_search(vector<int> arr, int l, int r, int x) {
    if ( r >= l ) {
      int mid = l + ( r - l ) / 2;
      if ( arr [ mid ] == x ) return mid;
      if ( arr [ mid ] > x ) return binary_search ( arr, l, mid - 1, x );
      return binary_search ( arr, mid + 1, r, x );
    }
    return - 1;
  }