58. Length of Last Word

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題目敘述

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.

Substring A substring is a contiguous non-empty sequence of characters within a string.

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.

解題思路

Solution

class Solution {
    public int lengthOfLastWord(String s) {
        String[] words = s.split(" ");
        
        for(int i = words.length - 1; i >= 0; i--) {
            if(words[i].length() > 0) {
                return words[i].length();
            }
        }

        return 0;
    }
}

#include <string>
#include <sstream>
#include <vector>
using namespace std;

class Solution {
public:
    int lengthOfLastWord(string s) {
        vector<string> words;
        stringstream ss(s);
        string word;
        while (ss >> word) {
            words.push_back(word);
        }
        if (words.empty()) {
            return 0;
        }
        return words.back().length();
    }
};