comefrom: <awangdev>760. Find Anagram Mappings_1.java
code: public int[] anagramMappings(int[] A, int[] B) {
          if (A == null || B == null || A.length == 0) {
              return null;
          }
  
          int[] result = new int[A.length];
          Map<Integer, ArrayList<Integer>> map = new HashMap<>();
          
          for (int i = 0; i < B.length; i++) {
              map.putIfAbsent(B[i], new ArrayList<>());
              map.get(B[i]).add(i);
          }
          
          for (int i = 0; i < A.length; i++) {
              ArrayList<Integer> list = map.get(A[i]);
              result[i] = list.get(0);
              list.remove(0);            
          }
          return result;
      }
masked: public int [ ] sample_funcname ( int [ ] var_0 , int [ ] var_1 ) {
    if ( var_0 == null || var_1 == null || var_0 . length == 0 ) {
      return null ;
    }
    int [ ] var_5 = new int [ var_0 . length ] ;
    Map < Integer , ArrayList < Integer >> var_10 = new HashMap < > ( ) ;
    for ( int var_11 = 0 ;
    var_11 < var_1 . length ;
    var_11 ++ ) {
      var_10 . putIfAbsent ( var_1 [ var_11 ] , new ArrayList < > ( ) ) ;
      var_10 . get ( var_1 [ var_11 ] ) . add ( var_11 ) ;
    }
    for ( int var_11 = 0 ;
    var_11 < var_0 . length ;
    var_11 ++ ) {
      ArrayList < Integer > var_15 = var_10 . get ( var_0 [ var_11 ] ) ;
      var_5 [ var_11 ] = var_15 . get ( 0 ) ;
      var_15 . remove ( 0 ) ;
    }
    return var_5 ;
  }
  