title: Find Maximum Average Subarray Of K Length
signature: class Solution {
  
      public Integer findMaximumAverageSubarrayOfKLength(ArrayList<Integer> arr, Integer n, Integer k) {
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 k, Integer expected){
          try{
              Driver driver = new Driver();
              if (driver.run(arr, n, k,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(2, 4, 6, 19, 21, 23, 32, 34, 47, 51, 56, 57, 57, 65, 68, 68, 69, 70, 71, 73, 74, 74, 77, 77, 79, 82, 82, 86, 87, 87, 88, 89, 90, 91, 92)), 29, 20, 9);
          System.out.println(String.format("%s%s","TEST-0...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(24, 62, -32, -28, 42, -46, -96, -70, -68, 60, 44, 34, -30, 96, -26, 92, 62, 42, -46, -38, 44, 54, -94, 52, 66, 68, -96, -58, 84, -2, 66, 30, 42)), 23, 31, -1);
          System.out.println(String.format("%s%s","TEST-1...",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, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1)), 32, 31, 1);
          System.out.println(String.format("%s%s","TEST-2...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(94, 6, 48, 34, 31)), 4, 3, 0);
          System.out.println(String.format("%s%s","TEST-3...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(-98, -88, -82, -80, -76, -70, -70, -60, -60, -52, -50, -46, -44, -44, -44, -20, -18, -12, -12, -12, -10, -8, -6, -4, 4, 4, 18, 28, 32, 34, 42, 42, 44, 46, 48, 54, 60, 70, 70, 72, 78, 78, 78, 78, 84, 86, 90, 96, 98)), 45, 30, 15);
          System.out.println(String.format("%s%s","TEST-4...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0)), 15, 8, 4);
          System.out.println(String.format("%s%s","TEST-5...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(1, 5, 13, 17, 26, 26, 32, 35, 38, 38, 39, 45, 52, 58, 60, 61, 62, 63, 82, 83, 85, 89, 89, 91)), 13, 22, -1);
          System.out.println(String.format("%s%s","TEST-6...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(-68, -52, 4, -90, 90, 88, 38, -18, 86, 4, 14, -32, -14, -44, -88, -50, -12, -26, -68, -20, -30, 22, 0, 14, -40, 58, -6, 28, -44, 8, 28, 96, -46, -12)), 32, 22, 4);
          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, 1, 1, 1)), 13, 11, 2);
          System.out.println(String.format("%s%s","TEST-8...",result));    
      
          result = validateSolution(new ArrayList<>(Arrays.asList(17, 33, 36, 34, 32, 10, 37, 48, 47, 32, 21, 18, 75, 8, 18, 52, 21, 73, 25, 25, 80, 32, 10, 24, 1, 89, 7, 42, 86, 85, 73, 12, 20, 20, 1, 74, 77, 4, 24, 74, 8)), 20, 28, -1);
          System.out.println(String.format("%s%s","TEST-9...",result));    
      
      }
  }
  
  class Driver{
      public boolean run(ArrayList<Integer> arr, Integer n, Integer k, Integer expected){
  
          PLACEHOLDER_CLS_NAME sol = new PLACEHOLDER_CLS_NAME();
          return validateSolution(sol.PLACEHOLDER_FN_NAME(arr, n, k),expected);
      }
      
      public boolean validateSolution(Integer actual, Integer expected){
          return actual.equals(expected);
      }
  }
  
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
source_py: def find_maximum_average_subarray_of_k_length(arr, n, k):
      if (k > n):
          return (- 1)
      csum = ([0] * n)
      csum[0] = arr[0]
      for i in range(1, n):
          csum[i] = (csum[(i - 1)] + arr[i])
      max_sum = csum[(k - 1)]
      max_end = (k - 1)
      for i in range(k, n):
          curr_sum = (csum[i] - csum[(i - k)])
          if (curr_sum > max_sum):
              max_sum = curr_sum
              max_end = i
      return ((max_end - k) + 1)
source_cpp: int find_maximum_average_subarray_of_k_length(vector<int> arr, int n, int k) {
    if ( k > n ) return - 1;
    int * csum = new int [ n ];
    csum [ 0 ] = arr [ 0 ];
    for ( int i = 1;
    i < n;
    i ++ ) csum [ i ] = csum [ i - 1 ] + arr [ i ];
    int max_sum = csum [ k - 1 ], max_end = k - 1;
    for ( int i = k;
    i < n;
    i ++ ) {
      int curr_sum = csum [ i ] - csum [ i - k ];
      if ( curr_sum > max_sum ) {
        max_sum = curr_sum;
        max_end = i;
      }
    }
    delete [ ] csum;
    return max_end - k + 1;
  }