comefrom: <gouthampradhan>hashing_LargestUniqueNumber_1.java
code: public int largestUniqueNumber(int[] A) {
      Map<Integer, Integer> map = new HashMap<>();
      for (int i : A) {
        map.putIfAbsent(i, 0);
        int v = map.get(i) + 1;
        map.put(i, v);
      }
      int max = -1;
      for (int k : map.keySet()) {
        if (map.get(k) == 1) {
          max = Math.max(max, k);
        }
      }
      return max;
    }
masked: public int sample_funcname ( int [ ] var_0 ) {
    Map < Integer , Integer > var_1 = new HashMap < > ( ) ;
    for ( int var_2 : var_0 ) {
      var_1 . putIfAbsent ( var_2 , 0 ) ;
      int var_3 = var_1 . get ( var_2 ) + 1 ;
      var_1 . put ( var_2 , var_3 ) ;
    }
    int max = - 1 ;
    for ( int var_4 : var_1 . keySet ( ) ) {
      if ( var_1 . get ( var_4 ) == 1 ) {
        max = Math . max ( max , var_4 ) ;
      }
    }
    return max ;
  }
  