53 · Reverse Words in a String - LintCode

# Description

Given an input string, reverse the string word by word.

What constitutes a word?
A sequence of non-space characters constitutes a word and some words have punctuation at the end.
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.

# Example

Example 1:

Input:

s = "the sky is blue"

Output:

"blue is sky the"

Explanation:

return a reverse the string word by word.

use String Builder
check if the String array[index] equals to ""
append a space " " when the result.length > 0, so the first one will never add a " ";
remember StringBuilder has to use toString()

	public class Solution {
	/**
	* @param s: A string
	* @return: A string
	*/
	public String reverseWords(String s) {
	StringBuilder res = new StringBuilder();
	String[] sArray = s.split(" ");
	for (int i = sArray.length - 1; i >= 0; i--){
	if (!sArray[i].equals("")){
	if (res.length() > 0) {
	res.append(" ");
	}
	res.append(sArray[i]);
	}

	}
	return res.toString();
	}
	}