【数组】面试题 01.01. 判定字符是否唯一

 1 class Solution {
 2 public:
 3     bool isUnique(string astr) 
 4     {
 5         int mark = 0;
 6         for (int i = 0; i < astr.size(); i++)
 7         {
 8             int move_bit = astr[i] - ‘a‘;
 9             if ((mark & (1 << move_bit)) != 0)
10             {
11                 return false;
12             }
13             else
14             {
15                 mark |= (1 << move_bit);
16             }
17         }
18         return true;
19     }
20 };