title: Largest Subarray With Equal Number Of 0S And 1S 1
signature: largestSubarrayWithEqualNumberOf0SAnd1S1 :: [Integer] -> Integer -> Integer
  largestSubarrayWithEqualNumberOf0SAnd1S1 arr n = 
test_code: import Text.Printf
  import Control.Exception (catch, SomeException)
  import Data.Typeable
  import qualified Data.List as List
  import qualified Data.Map as Map
  import qualified Data.Set as Set
  
  -- SOLUTION CODE
  -- ============================================
  
  PLACEHOLDER_CODE_BODY
  
  -- TESTING CODE 
  -- ============================================
  validateSolution :: Integer -> Integer -> Bool
  validateSolution actual expected = do
      actual == expected
  
  
  driver :: [Integer] -> Integer -> Integer -> String
  driver arr n expected = do
      if (validateSolution (PLACEHOLDER_FN_NAME arr n) expected)
          then "PASSED"
      else "FAILED"
  
  main = do
      printf "TEST-0...%s\n" (driver ([1, 1, 1, 1, 1, 1, 1, 1, 1, 42, 60, 66, 69, 70, 70, 73, 74, 80, 99]) (9) (0) )
  
      printf "TEST-1...%s\n" (driver ([1, -66]) (1) (0) )
  
      printf "TEST-2...%s\n" (driver ([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]) (19) (0) )
  
      printf "TEST-3...%s\n" (driver ([1, 1, 1, 1, 1, 1, 1, 1, 26, 44, 32]) (8) (0) )
  
      printf "TEST-4...%s\n" (driver ([1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 72, 74, 86, 92, 94]) (34) (0) )
  
      printf "TEST-5...%s\n" (driver ([1, 1, 1, 1, 1, 1, 0, 0, 0]) (4) (0) )
  
      printf "TEST-6...%s\n" (driver ([1, 64, 86]) (1) (0) )
  
      printf "TEST-7...%s\n" (driver ([1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, -68, 12, -44, 62, 60, -34, -52, 18]) (17) (0) )
  
      printf "TEST-8...%s\n" (driver ([0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1]) (9) (0) )
  
      printf "TEST-9...%s\n" (driver ([1, 1, 1, 1, 1, 1, 1, 1, 53]) (8) (0) )
  
source_py: def largest_subarray_with_equal_number_of_0s_and_1s_1(arr, n):
      hash_map = {
          
      }
      curr_sum = 0
      max_len = 0
      ending_index = (- 1)
      for i in range(0, n):
          if (arr[i] == 0):
              arr[i] = (- 1)
          else:
              arr[i] = 1
      for i in range(0, n):
          curr_sum = (curr_sum + arr[i])
          if (curr_sum == 0):
              max_len = (i + 1)
              ending_index = i
          if ((curr_sum + n) in hash_map):
              max_len = max(max_len, (i - hash_map[(curr_sum + n)]))
          else:
              hash_map[curr_sum] = i
      for i in range(0, n):
          if (arr[i] == (- 1)):
              arr[i] = 0
          else:
              arr[i] = 1
      print(((ending_index - max_len) + 1), end=' ')
      print('to', end=' ')
      print(ending_index)
      return max_len
source_cpp: int largest_subarray_with_equal_number_of_0s_and_1s_1(vector<int> arr, int n) {
    unordered_map < int, int > hM;
    int sum = 0;
    int max_len = 0;
    int ending_index = - 1;
    for ( int i = 0;
    i < n;
    i ++ ) arr [ i ] = ( arr [ i ] == 0 ) ? - 1 : 1;
    for ( int i = 0;
    i < n;
    i ++ ) {
      sum += arr [ i ];
      if ( sum == 0 ) {
        max_len = i + 1;
        ending_index = i;
      }
      if ( hM . find ( sum + n ) != hM . end ( ) ) {
        if ( max_len < i - hM [ sum + n ] ) {
          max_len = i - hM [ sum + n ];
          ending_index = i;
        }
      }
      else hM [ sum + n ] = i;
    }
    for ( int i = 0;
    i < n;
    i ++ ) arr [ i ] = ( arr [ i ] == - 1 ) ? 0 : 1;
    return max_len;
  }