LeetCode 557 - Reverse Words in a String III

https://leetcode.com/problems/reverse-words-in-a-string-iii

Given a string, you need to reverse the order of characters in each word within a sentence while still preserving whitespace and initial word order.

Example 1:

Input: "Let's take LeetCode contest"
Output: "s'teL ekat edoCteeL tsetnoc"

Note: In the string, each word is separated by single space and there will not be any extra space in the string.

https://discuss.leetcode.com/topic/85911/easiest-java-solution-9ms-similar-to-reverse-words-in-a-string-ii

Step 1. Convert the string to char[] array
Step 2. Whenever I encounter a space ' ' , I call the reverse function ( just to keep the code clean )
Step 3. Repeat till the end!

public String reverseWords(String s) 
{
    char[] s1 = s.toCharArray();
    int i = 0;
    for(int j = 0; j < s1.length; j++)
    {
        if(s1[j] == ' ')
        {
            reverse(s1, i, j - 1);
            i = j + 1;
        }
    }
    reverse(s1, i, s1.length - 1);
    return new String(s1);
}

public void reverse(char[] s, int l, int r)
{
 while(l < r)
 {
  char temp = s[l];
  s[l] = s[r];
  s[r] = temp;
  l++; r--;
 }
}

Yes your solution will work. But I think my solution will be faster because you are checking (j == n) every time and performing i = j + 1 for the last call which is unnecessary.

my solution - Run time : 9ms (94.42 %)
yours - Run time : 10ms (88.72 %)

    public String reverseWords(String s) {
        int n = s.length();
        char[] c = s.toCharArray();
        for (int i = 0, j = 1; j <= n; j++) {
            if (j == n || c[j] == ' ') {
                reverse(c, i, j-1);
                i = j+1;
            }
        }
        return new String(c);
    }

    private void reverse(char[] c, int i, int j) {
        while (i < j) {
            char temp = c[i];
            c[i] = c[j];
            c[j] = temp;
            i++; j--;
        }
    }

https://discuss.leetcode.com/topic/85784/c-java-clean-code

    public String reverseWords(String s) {
        char[] ca = s.toCharArray();
        for (int i = 0; i < ca.length; i++) {
            if (ca[i] != ' ') {   // when i is a non-space
                int j = i;
                while (j + 1 < ca.length && ca[j + 1] != ' ') { j++; } // move j to the end of the word
                reverse(ca, i, j);
                i = j;
            }
        }
        return new String(ca);
    }

    private void reverse(char[] ca, int i, int j) {
        for (; i < j; i++, j--) {
            char tmp = ca[i];
            ca[i] = ca[j];
            ca[j] = tmp;
        }
    }

https://discuss.leetcode.com/topic/85744/java-solution

public String reverseWords(String s) {
    String[] strs = s.split(" ");
    StringBuffer sb = new StringBuffer();
    for(String str: strs){
        StringBuffer temp = new StringBuffer(str);
        sb.append(temp.reverse());
        sb.append(" ");
    }
    sb.setLength(sb.length()-1);
    return sb.toString();
}