class Solution {
    public char findTheDifference(String s, String t) {

   char[]  schar = s.toCharArray();//将字符串转换为字符数组 
   char[]  tchar = t.toCharArray();
   Arrays.sort(schar);//对字符数组进行重新排序
   Arrays.sort(tchar);
   for(int i = 0; i<schar.length; i++){//遍历数组
       if(schar[i]!=tchar[i]){ //比较不相同的字符
         return tchar[i]; 
       }
   }

 return tchar[s.length()];  //返回字符串
   }
}