title: Count Pairs Difference Equal K 1
signature: pub fn count_pairs_difference_equal_k_1(arr: Vec<i32>, n: i32, k: 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, k: i32, expected: i32)->String{
      if validate_solution(PLACEHOLDER_FN_NAME(arr, n, k), expected) {
        return "PASSED".to_string();
      };
      return "FAILED".to_string();
  
  }
  
  fn main() {
      println!("TEST-0...{}", driver(
        Vec::from([5, 5, 10, 19, 29, 32, 40, 60, 65, 70, 72, 89, 92]), 7, 12, 
        0
      ));
      
      println!("TEST-1...{}", driver(
        Vec::from([-98, -90, -88, -82, -80, -78, -74, -74, -72, -62, -58, -58, -56, -52, -48, -46, -38, -38, -30, -12, -10, 4, 8, 8, 14, 22, 24, 26, 36, 40, 40, 48, 56, 58, 58, 58, 60, 62, 64, 68, 68, 74, 84]), 24, 36, 
        7
      ));
      
      println!("TEST-2...{}", driver(
        Vec::from([0, 0, 1]), 1, 1, 
        0
      ));
      
      println!("TEST-3...{}", driver(
        Vec::from([1, 7, 13, 14, 16, 29, 34, 42, 44, 49, 59, 62, 65, 66, 70, 71, 73, 73, 76, 80, 96, 96]), 12, 16, 
        1
      ));
      
      println!("TEST-4...{}", driver(
        Vec::from([-98, -88, -58, -56, -48, -34, -22, -18, -14, -14, -8, -4, -2, 2, 18, 38, 42, 46, 54, 68, 70, 90, 94, 96, 98]), 23, 22, 
        4
      ));
      
      println!("TEST-5...{}", driver(
        Vec::from([0, 1, 1]), 2, 1, 
        1
      ));
      
      println!("TEST-6...{}", driver(
        Vec::from([11, 43, 50, 58, 60, 68, 75]), 4, 4, 
        0
      ));
      
      println!("TEST-7...{}", driver(
        Vec::from([-80, -56, -10, 0, 6, 8, 24, 42, 52, 86, 88, 94]), 11, 9, 
        0
      ));
      
      println!("TEST-8...{}", driver(
        Vec::from([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]), 29, 30, 
        0
      ));
      
      println!("TEST-9...{}", driver(
        Vec::from([4, 7, 9, 9, 14, 34, 34, 36, 50, 54, 80, 81, 99]), 9, 8, 
        0
      ));
      
  }
source_py: def count_pairs_difference_equal_k_1(arr, n, k):
      count = 0
      arr.sort()
      l = 0
      r = 0
      while (r < n):
          if ((arr[r] - arr[l]) == k):
              count += 1
              l += 1
              r += 1
          elif ((arr[r] - arr[l]) > k):
              l += 1
          else:
              r += 1
      return count
source_cpp: int count_pairs_difference_equal_k_1(vector<int> arr, int n, int k) {
    int count = 0;
    sort(arr.begin(), arr.end());
    int l = 0;
    int r = 0;
    while ( r < n ) {
      if ( arr [ r ] - arr [ l ] == k ) {
        count ++;
        l ++;
        r ++;
      }
      else if ( arr [ r ] - arr [ l ] > k ) l ++;
      else r ++;
    }
    return count;
  }