solves reverse words in a string

Author: anishLearnsToCode

Diff for: README.md

@@ -134,7 +134,7 @@
 | 147  | [Insertion Sort List](https://leetcode.com/problems/insertion-sort-list)                                                                                  |                                                                [![Java](assets/java.png)](src/InsertionSortList.java)                                                                |                                                                                                                                   |
 | 148  | [Sort List](https://leetcode.com/problems/sort-list)                                                                                                      |                                                                    [![Java](assets/java.png)](src/SortList.java)                                                                     |                                                                                                                                   |
 | 150  | [Evaluate Reverse Polish Notation](https://leetcode.com/problems/evaluate-reverse-polish-notation)                                                        |                                                          [![Java](assets/java.png)](src/EvaluateReversePolishNotation.java)                                                          |                                                                                                                                   |
-| 151  | [Reverse Words in a String](https://leetcode.com/problems/reverse-words-in-a-string)                                                                      |                                                                                                                                                                                      |                                                                                                                                   |
+| 151  | [Reverse Words in a String](https://leetcode.com/problems/reverse-words-in-a-string)                                                                      |                                                              [![Java](assets/java.png)](src/ReverseWordsInAString.java)                                                              |                                                                                                                                   |
 | 152  | [Maximum Product Subarray](https://leetcode.com/problems/maximum-product-subarray)                                                                        |                                                                                                                                                                                      |                                                                                                                                   |
 | 153  | [Find Minimum in Rotated Sorted Array](https://leetcode.com/problems/find-minimum-in-rotated-sorted-array)                                                |                                                                                                                                                                                      |                                                                                                                                   |
 | 155  | [Min Stack](https://leetcode.com/problems/min-stack)                                                                                                      |                                          [![Java](assets/java.png)](src/MinStack.java) [![Python](assets/python.png)](python/min_stack.py)                                           |                                                                                                                                   |

Diff for: src/HelloWorld.java

@@ -1,7 +1,5 @@
 public class HelloWorld {
     public static void main(String[] args) {
-        System.out.println(Integer.parseInt("2"));
-        System.out.println(Integer.parseInt("-11"));
-        System.out.println(EvaluateReversePolishNotation.evalRPN(new String[] {"2", "-11", "-"}));
+        System.out.println(ReverseWordsInAString.reverseWords("   hello   world  "));
     }
 }

Diff for: src/ReverseWordsInAString.java

@@ -0,0 +1,19 @@
+// https://leetcode.com/problems/reverse-words-in-a-string
+// T: O(s)
+// S: O(s)
+
+public class ReverseWordsInAString {
+    private static final char SPACE = ' ';
+
+    public static String reverseWords(String s) {
+        final String[] words = s.split(" ");
+        final StringBuilder result = new StringBuilder();
+        for (int i = words.length - 1 ; i >= 0 ; i--) {
+            String word = words[i];
+            if (word.isEmpty()) continue;
+            result.append(word).append(SPACE);
+        }
+        result.deleteCharAt(result.length() - 1);
+        return result.toString();
+    }
+}