题目

Given a string s consists of upper/lower-case alphabets and empty space characters ' ', return the length of last word (last word means the last appearing word if we loop from left to right) in the string.

If the last word does not exist, return 0.

Note: A word is defined as a maximal substring consisting of non-space characters only.

Example:

Input: "Hello World"
Output: 5

来源：力扣（LeetCode）
链接：https://leetcode-cn.com/problems/length-of-last-word
著作权归领扣网络所有。商业转载请联系官方授权，非商业转载请注明出处。

解答思路

从尾到头进行遍历，当遇到单词的下一个空格时退出遍历即可。

注意项

后置多个空格的情况，取最后一个单词长度作为返回。

代码

package easy

import (
	"fmt"
	"testing"
)

/**
Given a string s consists of upper/lower-case alphabets and empty space characters ' ', return the length of last word (last word means the last appearing word if we loop from left to right) in the string.

If the last word does not exist, return 0.

Note: A word is defined as a maximal substring consisting of non-space characters only.

Example:

Input: "Hello World"
Output: 5

来源：力扣（LeetCode）
链接：https://leetcode-cn.com/problems/length-of-last-word
著作权归领扣网络所有。商业转载请联系官方授权，非商业转载请注明出处。
*/

func lengthOfLastWord(s string) int {
	var res int
	for i := len(s) - 1; i >= 0; i-- {
		if s[i] == ' ' {
			if res == 0 {
				continue
			}
			break
		}
		res++
	}
	return res
}

func TestLengthOfLastWord(t *testing.T) {
	fmt.Println(lengthOfLastWord("Hello World"))
	fmt.Println(lengthOfLastWord("b a  "))
}