updated readme

2017-04-30 18:30:26 -07:00
parent 9b6ef0f13b
commit 7145449310
57 changed files with 287 additions and 268 deletions
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+//     Author: Rodney Shaghoulian
+//     Github: github.com/rshaghoulian
+// HackerRank: hackerrank.com/rshaghoulian
+
+import java.util.Scanner;
+import java.util.HashSet;
+
+/*
+
+We are given an increasing input sequence, so no duplicate values exist.
+
+For each element in the sequence that we traverse, we save it in a HashSet. Let's call this element "k". 
+Our HashSet needs to have 3 elements, which we'll call i, j, k, that create a "beautiful triplet" as explained in the problem statement. 
+When we come across element "k", we check to see if our HashSet also has elements "i" and "j". 
+This is done by noting that we need to have a[i] + 2*d == a[j] + d == a[k] to have a beautiful triplet.
+
+Time  Complexity: O(n)
+Space Complexity: O(n)
+
+*/
+public class Solution {
+    public static void main(String[] args) {
+        /* Initialize variables */
+        HashSet<Integer> set = new HashSet<>();
+        Scanner scan = new Scanner(System.in);
+        int size     = scan.nextInt();
+        int d        = scan.nextInt();
+        int count    = 0;
+
+        /* Solve in 1 pass through values */
+        for (int i = 0; i < size; i++) {
+            int num = scan.nextInt();
+            if (set.contains(num - d) && set.contains(num - 2 * d)) {
+                count++;
+            }
+            set.add(num);
+        }
+        
+        scan.close();
+        System.out.println(count);
+    }
+}