58. Length of Last Word

难度: Easy

题目描述

Given a string s consisting of words and spaces, return the length of the last word in the string.

A word is a maximal substring consisting of non-space characters only.

 

Example 1:

Input: s = "Hello World"
Output: 5
Explanation: The last word is "World" with length 5.

Example 2:

Input: s = "   fly me   to   the moon  "
Output: 4
Explanation: The last word is "moon" with length 4.

Example 3:

Input: s = "luffy is still joyboy"
Output: 6
Explanation: The last word is "joyboy" with length 6.

 

Constraints:

• 1 <= s.length <= 104
• s consists of only English letters and spaces ' '.
• There will be at least one word in s.

解题思路

代码实现

解决方案

java

class Solution {
    public int lengthOfLastWord(String s) {
        int first = s.length();
        int second = -1;

        for (int i = s.length() - 1; i > -1; i--) {
            if (s.charAt(i) != ' ' && first > s.length() - 1) {
                first = i;
            }
            if (s.charAt(i) == ' ' && first < s.length()) {
                second = i;
                break;
            }
        }
        return first - second;

    }
}