title: Longest Subarray Count 1S One Count 0S
signature: class Solution {
  
      public Integer longestSubarrayCount1SOneCount0S(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, Integer 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(6, 10, 31, 35)), 2, 1);
          System.out.println(String.format("%s%s","TEST-0...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(4, 88, -72, 28, -54, 32, -34)), 6, 5);
          System.out.println(String.format("%s%s","TEST-1...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(0, 0, 0, 1, 1, 1, 1, 1, 1)), 4, 1);
          System.out.println(String.format("%s%s","TEST-2...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(39, 22, 15, 10, 34, 87, 46, 83, 74, 77, 61, 90, 43, 67, 64, 72, 92, 52, 68, 53, 67, 32, 82, 76, 76, 47, 74, 47, 8, 80, 85, 58, 75)), 26, 9);
          System.out.println(String.format("%s%s","TEST-3...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(-82, -58, -50, -30, -14, -4, -2, -2, 0, 22, 36, 58, 70, 80, 80, 82, 84, 90)), 14, 11);
          System.out.println(String.format("%s%s","TEST-4...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(1, 0, 1, 0, 0, 1, 1, 1, 0, 0, 1)), 7, 7);
          System.out.println(String.format("%s%s","TEST-5...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(4, 11, 17, 21, 21, 22, 30, 31, 36, 37, 39, 40, 45, 46, 47, 48, 52, 53, 53, 60, 60, 65, 66, 66, 67, 67, 87, 88, 91, 97)), 29, 9);
          System.out.println(String.format("%s%s","TEST-6...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(-4, -60, -78, -50, 64, 18, 0, 76, 12, 86, -22)), 7, 6);
          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, 1, 1, 1, 1, 1, 1, 1, 1, 1)), 17, 3);
          System.out.println(String.format("%s%s","TEST-8...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(4, 39, 50, 37, 71, 66, 55, 34, 1, 41, 34, 99, 69, 31)), 11, 9);
          System.out.println(String.format("%s%s","TEST-9...",result));    
      
      }
  }
  
  class Driver{
      public boolean run(ArrayList<Integer> arr, Integer n, Integer expected){
  
          PLACEHOLDER_CLS_NAME sol = new PLACEHOLDER_CLS_NAME();
          return validateSolution(sol.PLACEHOLDER_FN_NAME(arr, n),expected);
      }
      
      public boolean validateSolution(Integer actual, Integer expected){
          return actual.equals(expected);
      }
  }
  
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
source_py: def longest_subarray_count_1s_one_count_0s(arr, n):
      um = {i: 0 for i in range(10)}
      sum = 0
      maxLen = 0
      for i in range(n):
          if (arr[i] == 0):
              sum += (- 1)
          else:
              sum += 1
          if (sum == 1):
              maxLen = (i + 1)
          elif (sum not in um):
              um[sum] = i
          if ((sum - 1) in um):
              if (maxLen < (i - um[(sum - 1)])):
                  maxLen = (i - um[(sum - 1)])
      return maxLen
source_cpp: int longest_subarray_count_1s_one_count_0s(vector<int> arr, int n) {
    unordered_map < int, int > um;
    int sum = 0, maxLen = 0;
    for ( int i = 0;
    i < n;
    i ++ ) {
      sum += arr [ i ] == 0 ? - 1 : 1;
      if ( sum == 1 ) maxLen = i + 1;
      else if ( um . find ( sum ) == um . end ( ) ) um [ sum ] = i;
      if ( um . find ( sum - 1 ) != um . end ( ) ) {
        if ( maxLen < ( i - um [ sum - 1 ] ) ) maxLen = i - um [ sum - 1 ];
      }
    }
    return maxLen;
  }