LeetCode – Refresh – Length of Last Word

Tried it with spliting words method. But need to check empty situation.

 1 class Solution {
 2 public:
 3     int lengthOfLastWord(const char *s) {
 4         int len = strlen(s);
 5         if (len == 0) return 0;
 6         for (int i = len-1; i >= 0; i--) {
 7             if (s[i] == ‘ ‘) {
 8                 len = i;
 9             } else if (i == 0 || s[i-1] == ‘ ‘) {
10                 return len - i;
11             }
12         }
13     }
14 };

This method uses a flag to record whether we have encountered real chars before.

 1 class Solution {
 2 public:
 3     int lengthOfLastWord(const char *s) {
 4         int len = strlen(s), result = 0;
 5         bool flag = false;
 6         for (int i = len-1; i >= 0; i--) {
 7             if (s[i] == ‘ ‘) {
 8                 if (flag) return result;
 9             } else {
10                 flag = true;
11                 result++;
12             }
13         }
14         return result;
15     }
16 };