ReverseWordsInAString : Accepted

gouthampradhan · gouthampradhan · commit 8ecc71848319 · 2017-07-04T23:56:30.000+02:00
diff --git a/README.md b/README.md
@@ -145,6 +145,7 @@ My accepted leetcode solutions to some of the common interview problems.
 
 - [First Unique Character In a String](problems/src/string/FirstUniqueCharacterInAString.java) (Easy)
 - [Repeated Substring Pattern](problems/src/string/RepeatedSubstringPattern.java) (Easy)
+- [Reverse Words In a String](problems/src/string/ReverseWordsInAString.java) (Medium)
 - [ReverseWords II](problems/src/string/ReverseWordsII.java) (Medium)
 - [String to Integer](problems/src/string/StringToInteger.java) (Medium)
 - [Text Justification](problems/src/string/TextJustification.java) (Hard)
diff --git a/problems/src/string/ReverseWordsInAString.java b/problems/src/string/ReverseWordsInAString.java
@@ -0,0 +1,49 @@
+package string;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.StringTokenizer;
+
+/**
+ * Created by gouthamvidyapradhan on 04/07/2017.
+ * Given an input string, reverse the string word by word.
+
+ For example,
+ Given s = "the sky is blue",
+ return "blue is sky the".
+
+ Clarification:
+ What constitutes a word?
+ A sequence of non-space characters constitutes a word.
+ Could the input string contain leading or trailing spaces?
+ Yes. However, your reversed string should not contain leading or trailing spaces.
+ How about multiple spaces between two words?
+ Reduce them to a single space in the reversed string.
+ */
+public class ReverseWordsInAString {
+    public static void main(String[] args) throws Exception{
+        System.out.println(new ReverseWordsInAString().reverseWords("  the     sky is blue"));
+    }
+
+    public String reverseWords(String s) {
+        if(s == null || s.isEmpty()) return "";
+        StringBuilder sb = new StringBuilder(s.trim());
+        String reverse = sb.reverse().toString();
+        StringTokenizer st = new StringTokenizer(reverse, " ");
+        List<String> list = new ArrayList<>();
+        while(st.hasMoreTokens()){
+            list.add(st.nextToken());
+        }
+        for(int i = 0, l = list.size(); i < l; i ++){
+            String str = list.get(i);
+            String newStr = new StringBuilder(str).reverse().toString();
+            list.set(i, newStr);
+        }
+        StringBuilder result = new StringBuilder();
+        for(String str : list){
+            result.append(str).append(" ");
+        }
+        return result.toString().trim();
+    }
+
+}
