Added extra solutions to HackerRank problems

Author: dayday25

Pairs.ipynb

@@ -1,5 +1,58 @@
 {
  "cells": [
+ {
+ "cell_type": "code",
+ "execution_count": null,
+ "metadata": {},
+ "outputs": [],
+ "source": [
+ "#!/bin/python3\n",
+ "\n",
+ "import math\n",
+ "import os\n",
+ "import random\n",
+ "import re\n",
+ "import sys\n",
+ "\n",
+ "# PROBLEM: Given an array of integers (arr) and a target value (k) determine the number of pairs of array elements that have a difference equal to target value\n",
+ "# https://www.hackerrank.com/challenges/pairs/problem?isFullScreen=true\n",
+ "\n",
+ "# ===== EXAMPLE ===== #\n",
+ "# k = 1\n",
+ "# arr = [1,2,3,4]\n",
+ "# ---> (2,1), (3,2), (4,3) = 3 Pairs\n",
+ "\n",
+ "# BRUTE FORCE APPROACH:\n",
+ "# STEP 1: Generate every combination of pairs (i,j) in the array\n",
+ "# STEP 2: Calculate the difference between i and j\n",
+ "# STEP 3: If the difference equals equals the target value, increment count by 1\n",
+ "\n",
+ "def pairs(k, arr):\n",
+ " count = 0\n",
+ " for i in range(len(arr)):\n",
+ " for j in range(i+1, len(arr)):\n",
+ " if (arr[i] - arr[j] == k) or (arr[j] - arr[i] == k):\n",
+ " count += 1\n",
+ " return count\n",
+ "\n",
+ "if __name__ == '__main__':\n",
+ " fptr = open(os.environ['OUTPUT_PATH'], 'w')\n",
+ "\n",
+ " first_multiple_input = input().rstrip().split()\n",
+ "\n",
+ " n = int(first_multiple_input[0])\n",
+ "\n",
+ " k = int(first_multiple_input[1])\n",
+ "\n",
+ " arr = list(map(int, input().rstrip().split()))\n",
+ "\n",
+ " result = pairs(k, arr)\n",
+ "\n",
+ " fptr.write(str(result) + '\\n')\n",
+ "\n",
+ " fptr.close()\n"
+ ]
+ },
  {
  "cell_type": "code",
  "execution_count": null,
@@ -20,7 +73,7 @@
  " # k = 1\n",
  " # arr = [1,2,3,4]\n",
  " # ---> (2,1), (3,2), (4,3) = 3 Pairs\n",
- "# APPROACH:\n",
+ "# OPTIMIZED APPROACH:\n",
  "# STEP 1: Generate every combination of pairs (i,j) in the array\n",
  "# STEP 2: Calculate the difference between i and j\n",
  "# STEP 3: If the difference equals equals the target value, increment count by 1\n",