LeetCode 58. Length of Last Word

Given a string s consists of upper/lower-case alphabets and empty space characters ' ', return the length of last word in the string.

If the last word does not exist, return 0.

Note: A word is defined as a character sequence consists of non-space characters only.

Example:

Input: "Hello World"
Output: 5

计算最后一个word的长度，那就从后到前开始吧。

class Solution {
    public int lengthOfLastWord(String s) {
        if(s == null || s.length() == 0) {
            return 0;
        }
        int index = s.length() - 1;
        int cnt = 0;
        while(index >= 0) {
            if(!(s.charAt(index) + "").equals(" ")) {
                cnt++;
            } else if(cnt != 0){
                return cnt;
            }
            index--;
        }
        return cnt;
        
    }
}

提交结果：

Runtime: 2 ms, faster than 100.00% of Java online submissions for Length of Last Word.

Memory Usage: 34.9 MB, less than 48.74% of Java online submissions for Length of Last Word.