LeetCode: Length of Last Word

初始length的时候忘给了0了，2次过

class Solution {
public:
    int lengthOfLastWord(const char *s) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        int beg = 0;
        int length = 0;
        while (*(s+beg) != '\0') {
            if (*(s+beg) == ' ') beg++;
            else {
                length = 0;
                while (*(s+beg+length) != '\0') {
                    if (*(s+beg+length) >= 'a' && *(s+beg+length) <= 'z' || *(s+beg+length) >= 'A' && *(s+beg+length) <= 'Z')
                        length++;
                    else break;
                }
                beg += length;
            }
        }
        return length;
    }
};

 后来写了个更加精简的代码

class Solution {
public:
    int lengthOfLastWord(const char *s) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        string S;
        while (*s != '\0') S += *(s++);
        while (S.size() && S[S.size()-1] == ' ') S.erase(S.size()-1, 1);
        if (S.rfind(' ') == string::npos) return S.size();
        else return S.size() - S.rfind(' ') - 1;
    }
};

 C#

public class Solution {
    public int LengthOfLastWord(string s) {
        int lastAlpha = s.Length - 1;
        for (; lastAlpha >= 0; lastAlpha--) {
            if (s[lastAlpha] != ' ') break;
        }
        return lastAlpha == -1? 0 : lastAlpha - s.LastIndexOf(' ', lastAlpha);
    }
}