AcronymMaker

shekhargulati · shekhargulati · commit 9f853e8ac342 · 2016-03-16T11:48:46.000+05:30
diff --git a/java8/src/main/java/com/shekhargulati/codegolf/AcronymMaker.java b/java8/src/main/java/com/shekhargulati/codegolf/AcronymMaker.java
@@ -0,0 +1,26 @@
+package com.shekhargulati.codegolf;
+
+import java.util.Arrays;
+import java.util.List;
+
+import static java.util.stream.Collectors.joining;
+
+/**
+ * Your goal is to make a program that converts an input to its acronym.
+ * Your input is guaranteed to have only letters and spaces. The input will have exactly one space between words.
+ * You must output the acronym of the input.
+ */
+public class AcronymMaker {
+
+    private static final List<String> STOP_WORDS = Arrays.asList("and", "or", "by", "of");
+
+    public static String acronym(final String input) {
+        /*
+        Algorithm:
+        1. Split string into words
+        2. Filter out all the stopwords
+        3. Iterate over all the remaining words and take the first char and upper case it
+         */
+        return Arrays.stream(input.toLowerCase().split("\\s")).filter(word -> !STOP_WORDS.contains(word)).map(w -> String.valueOf(w.charAt(0)).toUpperCase()).collect(joining(""));
+    }
+}
diff --git a/java8/src/main/java/com/shekhargulati/tadm/ch04/examples/MergeSort.java b/java8/src/main/java/com/shekhargulati/tadm/ch04/examples/MergeSort.java
@@ -0,0 +1,37 @@
+package com.shekhargulati.tadm.ch04.examples;
+
+import java.util.Arrays;
+
+public class MergeSort {
+
+    public static void main(String[] args) {
+        System.out.println(Arrays.toString(mergeSort(new int[]{3, 2, 1, 4})));
+    }
+
+    public static int[] mergeSort(int[] arr) {
+        if (arr.length == 1) {
+            return arr;
+        }
+        int middle = arr.length / 2;
+        int[] left = mergeSort(Arrays.copyOfRange(arr, 0, middle));
+        int[] right = mergeSort(Arrays.copyOfRange(arr, middle, arr.length));
+        return merge(left, right, arr.length);
+    }
+
+    private static int[] merge(int[] left, int[] right, int length) {
+        int[] sorted = new int[length];
+        int[] smaller = ((left.length < right.length) ? left : right);
+        for (int i = 0; i < smaller.length; i++) {
+            if (left[i] <= right[i]) {
+                sorted[i] = left[i];
+            } else {
+                sorted[i] = right[i];
+            }
+        }
+        int[] greater = ((left.length > right.length) ? left : right);
+        for (int i = smaller.length; i < greater.length; i++) {
+            sorted[i] = greater[i];
+        }
+        return sorted;
+    }
+}
diff --git a/java8/src/test/java/com/shekhargulati/codegolf/AcronymMakerTest.java b/java8/src/test/java/com/shekhargulati/codegolf/AcronymMakerTest.java
@@ -0,0 +1,37 @@
+package com.shekhargulati.codegolf;
+
+import org.junit.Test;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.junit.Assert.assertThat;
+
+public class AcronymMakerTest {
+
+    @Test
+    public void acronymOfUnitedStatesOfAmericaIsUSA() throws Exception {
+        final String input = "United States of America";
+        final String acronym = AcronymMaker.acronym(input);
+        assertThat(acronym, equalTo("USA"));
+    }
+
+    @Test
+    public void acronymOfUnitedStatesOfAmericaIsUSA_lowercase() throws Exception {
+        final String input = "united states of america";
+        final String acronym = AcronymMaker.acronym(input);
+        assertThat(acronym, equalTo("USA"));
+    }
+
+    @Test
+    public void acronymOfLightAmplificationByStimulationOfEmittedRadiationIsLASER() throws Exception {
+        final String input = "Light Amplification by Stimulation of Emitted Radiation";
+        final String acronym = AcronymMaker.acronym(input);
+        assertThat(acronym, equalTo("LASER"));
+    }
+
+    @Test
+    public void acronymOfJordanOfTheWorldIsJTW() throws Exception {
+        final String input = "Jordan Of the World";
+        final String acronym = AcronymMaker.acronym(input);
+        assertThat(acronym, equalTo("JTW"));
+    }
+}
