Today I have done leetcode's April LeetCoding Challenge with cpp.

April LeetCoding Challenge 1

Description

Length of Last Word

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.

Solution

auto speedup = [](){
  cin.tie(nullptr);
  cout.tie(nullptr);
  ios::sync_with_stdio(false);
  return 0;
}();
class Solution {
public:
  int lengthOfLastWord(string s) {
    auto b = s.rbegin();
    while(b != s.rend() && isspace(*b)) ++b;
    int answer = 0;
    while(b != s.rend() && !isspace(*b)) {
      answer += 1;
      ++b;
    }
    return answer;
  }
};