README_EN.md

58. Length of Last Word

中文文档

Description

Given a string s consists of some words separated by spaces, return the length of the last word in the string. If the last word does not exist, return 0.

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

 

Example 1:

Input: s = "Hello World"
Output: 5

Example 2:

Input: s = " "
Output: 0

 

Constraints:

• 1 <= s.length <= 104
• s consists of only English letters and spaces ' '.

Solutions

Python3

class Solution:
    def lengthOfLastWord(self, s: str) -> int:
        last_word_length = 0
        meet_word = False
        for i in range(len(s) - 1, -1, -1):
            ch = ord(s[i])
            if ch >= 65 and ch <= 122:
                meet_word = True
                last_word_length += 1
            elif meet_word:
                break
        return last_word_length

Java

class Solution {
    public int lengthOfLastWord(String s) {
        int n = s.length();
        int lastWordLength = 0;
        boolean meetWord = false;
        for (int i = n - 1; i >= 0; --i) {
            char ch = s.charAt(i);
            if (ch >= 'A' && ch <= 'z') {
                meetWord = true;
                ++lastWordLength;
            } else if (meetWord) {
                break;
            }
        }
        return lastWordLength;
    }
}

Rust

impl Solution {
    pub fn length_of_last_word(s: String) -> i32 {
        let s = s.trim_end();
        if s.len() == 0 {
            return 0;
        }
        for (i, c) in s.char_indices().rev() {
            if c == ' ' {
                return (s.len() - i - 1) as i32;
            }
        }
        s.len() as i32
    }
}

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