LeetCode-58. Length of Last Word

Given a string s consists of upper/lower-case alphabets and empty space characters ' ', return the length of last word in the string.

If the last word does not exist, return 0.

Note: A word is defined as a character sequence consists of non-space characters only.

Example:

Input: "Hello World"
Output: 5

题解：

测试用例有点坑，所以超多踩的。

class Solution {
public:
  int lengthOfLastWord(string s) {
    int num = 0;
    int n = s.length();
    if (n == 0) {
      return 0;
    }
    while (s[n - 1] == ' ') {
      n--;
    }
    while (n >= 1 && s[n - 1] != ' ') {
      n--;
      num++;
    }
    return num;
  }
};