Compare two strings A and B, determine whether A contains all of the characters in B.

The characters in string A and B are all Upper Case letters.

Example

For A = "ABCD", B = "ACD", return true.

For A = "ABCD", B = "AABC", return false.

Note

The characters of B in A are not necessary continuous or ordered.

 

这道题也没太多好说的，cracking code interview提过这种小技巧

public class Solution {    /**     * @param A : A string includes Upper Case letters     * @param B : A string includes Upper Case letter     * @return :  if string A contains all of the characters in B return true else return false     */    public boolean compareStrings(String A, String B) {        // write your code here        if(A == null)            return false;                if(B == null || B.length() == 0)            return true;                int[] count = new int[26];                int lengthA = A.length();        int lengthB = B.length();                if(lengthB > lengthA)            return false;                for(int i = 0; i < lengthA; i++){            count[A.charAt(i) - 'A']++;        }                for(int i = 0; i < lengthB; i++){            count[B.charAt(i) - 'A']--;                        if(count[B.charAt(i) - 'A'] < 0)                return false;        }                return true;    }}