added nested list ii

Author: sagivo

README.md

@@ -26,6 +26,7 @@ This is my way of saying - change your interview style. There are lots of smart
 | [Sum 4 arrays](https://leetcode.com/problems/4sum-ii/description/) | [click](https://github.com/sagivo/algorithms/blob/master/src/4-sum.rb) |
 | [Reverse Linked List](https://leetcode.com/problems/reverse-linked-list/description/) | [click](https://github.com/sagivo/algorithms/blob/master/src/reverse-linked-list.rb) |
 | [Reverse String In-place](https://leetcode.com/problems/reverse-string/description/) | [click](https://github.com/sagivo/algorithms/blob/master/src/reverse-string-inplace.rb) |
+| [Nested List Weight Sum II](https://leetcode.com/problems/nested-list-weight-sum-ii/) | [click](https://github.com/sagivo/algorithms/blob/master/src/nested_list_weight_sum_ii.rb) |
 | [Symmetric Tree](https://leetcode.com/problems/symmetric-tree/) | [click](https://github.com/sagivo/algorithms/blob/master/src/mirror.rb) |
 | [Dijkstra's shortest path between two nodes](https://en.wikipedia.org/wiki/Dijkstra%27s_algorithm) | [click](https://github.com/sagivo/algorithms/blob/master/src/dijkstra.rb) |
 | [Kruskal's minimum spanning tree algorithm](http://en.wikipedia.org/wiki/Kruskal%27s_algorithm) | [click](https://github.com/sagivo/algorithms/blob/master/src/kruskal.rb) |

src/nested_list_weight_sum_ii.rb

@@ -0,0 +1,67 @@
+# This is the interface that allows for creating nested lists.
+# You should not implement it, or speculate about its implementation
+#
+#class NestedInteger
+# def is_integer()
+# """
+# Return true if this NestedInteger holds a single integer, rather than a nested list.
+# @return {Boolean}
+# """
+#
+# def get_integer()
+# """
+# Return the single integer that this NestedInteger holds, if it holds a single integer
+# Return nil if this NestedInteger holds a nested list
+# @return {Integer}
+# """
+#
+# def set_integer(value)
+# """
+# Set this NestedInteger to hold a single integer equal to value.
+# @return {Void}
+# """
+#
+# def add(elem)
+# """
+# Set this NestedInteger to hold a nested list and adds a nested integer elem to it.
+# @return {Void}
+# """
+#
+# def get_list()
+# """
+# Return the nested list that this NestedInteger holds, if it holds a nested list
+# Return nil if this NestedInteger holds a single integer
+# @return {NestedInteger[]}
+# """
+
+# @param {NestedInteger[]} nested_list
+# @return {Integer}
+
+def depth_sum_inverse(nested_list)
+ h = {}
+ lvl = 0
+
+ while nested_list.any?
+ q = []
+ lvl+=1
+ h[lvl] = 0
+
+ nested_list.each do |n|
+ if n.is_integer()
+ h[lvl] += n.get_integer
+ else
+ q << n.get_list()
+ end
+ end
+
+ nested_list = q.flatten
+ end
+
+ sum = 0
+
+ h.each do |k, v|
+ sum += ((lvl-k+1) * v)
+ end
+
+ sum
+end

src/phone.rb

@@ -26,7 +26,7 @@ def letters_for_number num
 def join_sets set, i = 0, str = '', result = []
  return result << str if str.size == set.size
  for item in set[i]
- join_sets set, i.succ, str + item.to_s, result
+ join_sets set, i + 1, str + item.to_s, result
  end
  result
 end