LeetCode: Length of Last Word

初始length的时候忘给了0了，2次过

 1 class Solution {

 2 public:

 3     int lengthOfLastWord(const char *s) {

 4         // Start typing your C/C++ solution below

 5         // DO NOT write int main() function

 6         int beg = 0;

 7         int length = 0;

 8         while (*(s+beg) != '\0') {

 9             if (*(s+beg) == ' ') beg++;

10             else {

11                 length = 0;

12                 while (*(s+beg+length) != '\0') {

13                     if (*(s+beg+length) >= 'a' && *(s+beg+length) <= 'z' || *(s+beg+length) >= 'A' && *(s+beg+length) <= 'Z')

14                         length++;

15                     else break;

16                 }

17                 beg += length;

18             }

19         }

20         return length;

21     }

22 };

 后来写了个更加精简的代码

 1 class Solution {

 2 public:

 3     int lengthOfLastWord(const char *s) {

 4         // Start typing your C/C++ solution below

 5         // DO NOT write int main() function

 6         string S;

 7         while (*s != '\0') S += *(s++);

 8         while (S.size() && S[S.size()-1] == ' ') S.erase(S.size()-1, 1);

 9         if (S.rfind(' ') == string::npos) return S.size();

10         else return S.size() - S.rfind(' ') - 1;

11     }

12 };

 C#

1 public class Solution {

2     public int LengthOfLastWord(string s) {

3         int lastAlpha = s.Length - 1;

4         for (; lastAlpha >= 0; lastAlpha--) {

5             if (s[lastAlpha] != ' ') break;

6         }

7         return lastAlpha == -1? 0 : lastAlpha - s.LastIndexOf(' ', lastAlpha);

8     }

9 }

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