title: Chocolate Distribution Problem
signature: pub fn chocolate_distribution_problem(arr: Vec<i32>, n: i32, m: i32) -> i32 {
test_code: use std::collections::HashMap;
  use std::collections::HashSet;
  use std::cmp::*;
  use std::collections::*;
  use std::fmt::*; 
  
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  pub fn validate_solution(actual: i32, expected: i32)->bool{
  return actual==expected
  }
  pub fn driver(arr: Vec<i32>, n: i32, m: i32, expected: i32)->String{
      if validate_solution(PLACEHOLDER_FN_NAME(arr, n, m), expected) {
        return "PASSED".to_string();
      };
      return "FAILED".to_string();
  
  }
  
  fn main() {
      println!("TEST-0...{}", driver(
        Vec::from([2, 5, 11, 23, 33, 35, 39, 51, 52, 56, 74, 76, 76, 79, 85, 88, 93, 98]), 16, 13, 
        65
      ));
      
      println!("TEST-1...{}", driver(
        Vec::from([-94, -94, -88, -84, -74, -70, -56, -50, -48, -42, -34, -24, -18, -14, 0, 4, 4, 16, 16, 30, 36, 42, 52, 56, 72, 74, 76, 84, 88]), 15, 28, 
        -1
      ));
      
      println!("TEST-2...{}", driver(
        Vec::from([0, 0, 1, 1, 1, 1]), 5, 5, 
        1
      ));
      
      println!("TEST-3...{}", driver(
        Vec::from([3, 4, 5, 5, 12, 16, 16, 16, 18, 29, 37, 38, 40, 43, 44, 49, 57, 60, 62, 63, 67, 69, 73, 74, 75, 76, 78, 84, 85, 86, 88, 89, 92]), 25, 18, 
        57
      ));
      
      println!("TEST-4...{}", driver(
        Vec::from([-98, -80, -50, -44, -42, -36, -36, -28, -10, -8, -4, -2, 2, 10, 18, 18, 26, 32, 36, 56, 80, 86, 88, 90]), 16, 12, 
        60
      ));
      
      println!("TEST-5...{}", driver(
        Vec::from([0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1]), 13, 14, 
        -1
      ));
      
      println!("TEST-6...{}", driver(
        Vec::from([13, 15, 62, 65, 87]), 3, 4, 
        -1
      ));
      
      println!("TEST-7...{}", driver(
        Vec::from([-92, -88, -88, -80, -76, -62, -60, -60, -50, -48, -36, -36, -32, -26, -14, -8, 4, 18, 18, 22, 28, 30, 30, 32, 48, 48, 58, 60, 64, 72, 78, 82, 94]), 31, 17, 
        90
      ));
      
      println!("TEST-8...{}", driver(
        Vec::from([0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1]), 9, 6, 
        1
      ));
      
      println!("TEST-9...{}", driver(
        Vec::from([17, 23, 25, 38, 40, 53, 58, 73, 77]), 8, 6, 
        35
      ));
      
  }
source_py: def chocolate_distribution_problem(arr, n, m):
      if ((m == 0) or (n == 0)):
          return 0
      arr.sort()
      if (n < m):
          return (- 1)
      min_diff = sys.maxsize
      first = 0
      last = 0
      i = 0
      while (((i + m) - 1) < n):
          diff = (arr[((i + m) - 1)] - arr[i])
          if (diff < min_diff):
              min_diff = diff
              first = i
              last = ((i + m) - 1)
          i += 1
      return (arr[last] - arr[first])
source_cpp: int chocolate_distribution_problem(vector<int> arr, int n, int m) {
    if ( m == 0 || n == 0 ) return 0;
    sort(arr.begin(), arr.end());
    if ( n < m ) return - 1;
    int min_diff = INT_MAX;
    int first = 0, last = 0;
    for ( int i = 0;
    i + m - 1 < n;
    i ++ ) {
      int diff = arr [ i + m - 1 ] - arr [ i ];
      if ( diff < min_diff ) {
        min_diff = diff;
        first = i;
        last = i + m - 1;
      }
    }
    return ( arr [ last ] - arr [ first ] );
  }