242. Effective letter heteronyms

242. Effective alphabetic words
     Given two strings s and t , Write a function to determine t Whether it is s Letter heteronym of .

Be careful ： if s and t Each character in the has the same number of occurrences , said s and t They are mutually alphabetic words .

Ideas ：
Use one 26 An array of lengths , Record the number of each character in a string .
Loop another string , Subtract one from the number of characters that appear .
Last , Each value of the array is 0. Is equal .

grammar ：

// Get the position of a character in the string 
String s = "abc";
char a = s.charAt(0);

integer array , By default, each element is 0.