Description (leetcode)

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 <= 10^4
  • s consists of only English letters and spaces ' '.
  • There will be at least one word in s.

submission

impl Solution {
    pub fn length_of_last_word(s: String) -> i32 {
        // reverse iterator, count non-space chars
        s.trim_end().chars().rev().take_while(|&c| c != ' ').count() as _
    }
}