LintCode: Compare Strings

C++
 1 class Solution {
 2 public:
 3     /**
 4      * @param A: A string includes Upper Case letters
 5      * @param B: A string includes Upper Case letter
 6      * @return:  if string A contains all of the characters in B return true 
 7      *           else return false
 8      */
 9     bool compareStrings(string A, string B) {
10         // write your code here
11         if (B == "") {
12             return true;
13         }
14         for (int i=0; i<B.size(); i++) {
15             int j = A.find_first_of(B[i]);
16             if (j == -1){
17                 return false;;
18             } else {
19                 A[j] = '-';
20             }
21         }
22         return true;
23     }
24 };