comefrom: <awangdev>Unique Binary Search Tree_2.java
code: public int numTrees(int n) {
          if (n <= 1) {
              return 1;
          }
          int[] count = new int[n + 1];
          count[0] = 1;
          count[1] = 1;
          for (int i = 2; i < n + 1; i++) {
              for (int j = 0; j < i; j++) {
                  count[i] += count[j] * count[i - j - 1];
              }
          }
          return count[n];
      }
masked: public int sample_funcname ( int var_0 ) {
    if ( var_0 <= 1 ) {
      return 1 ;
    }
    int [ ] var_1 = new int [ var_0 + 1 ] ;
    var_1 [ 0 ] = 1 ;
    var_1 [ 1 ] = 1 ;
    for ( int var_2 = 2 ;
    var_2 < var_0 + 1 ;
    var_2 ++ ) {
      for ( int var_3 = 0 ;
      var_3 < var_2 ;
      var_3 ++ ) {
        var_1 [ var_2 ] += var_1 [ var_3 ] * var_1 [ var_2 - var_3 - 1 ] ;
      }
    }
    return var_1 [ var_0 ] ;
  }
  