RansomNote


Given
 an 
arbitrary
 ransom
 note
 string 
and 
another 
string 
containing 
letters from
 all 
the 
magazines,
 write 
a 
function 
that 
will 
return 
true 
if 
the 
ransom 
 note 
can 
be 
constructed 
from 
the 
magazines ; 
otherwise, 
it 
will 
return 
false. 



Each 
letter
 in
 the
 magazine 
string 
can
 only 
be
 used 
once
 in
 your 
ransom
 note.

Note:

You may assume that both strings contain only lowercase letters.

canConstruct("a", "b") -> false
canConstruct("aa", "ab") -> false
canConstruct("aa", "aab") -> true

  1 public class Solution {
  2    public boolean canConstruct(String ransomNote, String magazine) {
  3         int[] arr = new int[26];
  4         for (int i = 0; i < magazine.length(); i++) {
  5             arr[magazine.charAt(i) - 'a']++;
  6         }
  7         for (int i = 0; i < ransomNote.length(); i++) {
  8             if(--arr[ransomNote.charAt(i)-'a'] < 0) {
  9                 return false;
 10             }
 11         }
 12         return true;
 13     }
 14 }