https://leetcode.com/problems/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.
For example,
Given s = “Hello World”,
return 5.
class Solution {
public:
int lengthOfLastWord(string s) {
size_t n = s.length();
size_t lb = 0, ub = n - 1;
reverse(s.begin(), s.end());
while (lb < n) { if (s[lb] == ‘ ‘) lb++; else break; }
while (ub >= 0) { if (s[ub] == ‘ ‘) ub--; else break; }
if (lb == n && ub == -1) return 0;
int ans = 0;
for (size_t i = lb; i <= ub; i++) {
if (s[i] != ‘ ‘) ans++;
else break;
}
return ans;
}
};
原文：http://www.cnblogs.com/GadyPu/p/5040115.html