title: Count Pairs Difference Equal K 1
signature: function countPairsDifferenceEqualK1(arr: Array<number>, n: number, k: number): number {
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;
  }
question_info.test_list: [{"idx": 0, "outputs": 0, "inputs": {"arr": [5, 5, 10, 19, 29, 32, 40, 60, 65, 70, 72, 89, 92], "n": 7, "k": 12}}, {"idx": 1, "outputs": 7, "inputs": {"arr": [-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], "n": 24, "k": 36}}, {"idx": 2, "outputs": 0, "inputs": {"arr": [0, 0, 1], "n": 1, "k": 1}}, {"idx": 3, "outputs": 1, "inputs": {"arr": [1, 7, 13, 14, 16, 29, 34, 42, 44, 49, 59, 62, 65, 66, 70, 71, 73, 73, 76, 80, 96, 96], "n": 12, "k": 16}}, {"idx": 4, "outputs": 4, "inputs": {"arr": [-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], "n": 23, "k": 22}}, {"idx": 5, "outputs": 1, "inputs": {"arr": [0, 1, 1], "n": 2, "k": 1}}, {"idx": 6, "outputs": 0, "inputs": {"arr": [11, 43, 50, 58, 60, 68, 75], "n": 4, "k": 4}}, {"idx": 7, "outputs": 0, "inputs": {"arr": [-80, -56, -10, 0, 6, 8, 24, 42, 52, 86, 88, 94], "n": 11, "k": 9}}, {"idx": 8, "outputs": 0, "inputs": {"arr": [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], "n": 29, "k": 30}}, {"idx": 9, "outputs": 0, "inputs": {"arr": [4, 7, 9, 9, 14, 34, 34, 36, 50, 54, 80, 81, 99], "n": 9, "k": 8}}]
question_info.entry_cls_name: Solution
question_info.test_code: 
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  function convertToString(value: any): string{
      return JSON.stringify(value, function (key, val) {
          if (val instanceof Set) {
              return Array.from(val);
          } return val;});
  }
  
  function validateSolution(actual: number, expected: number): boolean {
      return convertToString(actual) === convertToString(expected);
  }
  
  function driver(arr: Array<number>, n: number, k: number, expected:number): string {
      try{
          if (validateSolution(PLACEHOLDER_FN_NAME(arr, n, k),expected)){
              return "PASSED";
          }
          return "FAILED";
      } catch (error) {
        return error.name;
      }
      
  }
      
  function main(){
    let result = '';
    result = driver([5, 5, 10, 19, 29, 32, 40, 60, 65, 70, 72, 89, 92], 7, 12, 0);
    console.log(`TEST-0...${result}`);
  
    result = driver([-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);
    console.log(`TEST-1...${result}`);
  
    result = driver([0, 0, 1], 1, 1, 0);
    console.log(`TEST-2...${result}`);
  
    result = driver([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);
    console.log(`TEST-3...${result}`);
  
    result = driver([-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);
    console.log(`TEST-4...${result}`);
  
    result = driver([0, 1, 1], 2, 1, 1);
    console.log(`TEST-5...${result}`);
  
    result = driver([11, 43, 50, 58, 60, 68, 75], 4, 4, 0);
    console.log(`TEST-6...${result}`);
  
    result = driver([-80, -56, -10, 0, 6, 8, 24, 42, 52, 86, 88, 94], 11, 9, 0);
    console.log(`TEST-7...${result}`);
  
    result = driver([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);
    console.log(`TEST-8...${result}`);
  
    result = driver([4, 7, 9, 9, 14, 34, 34, 36, 50, 54, 80, 81, 99], 9, 8, 0);
    console.log(`TEST-9...${result}`);
  
  };
  
  main();
question_info.extension: ts
question_info.entry_fn_name: countPairsDifferenceEqualK1
question_info.test_case_ids: 0 1 2 3 4 5 6 7 8 9
question_info.commands: tsc --target es2020 --lib es5,dom,es2015,es2020 __FILENAME__
question_info.commands: node __FILENAME__.js