Leaves - Georgina

lib/max_subarray.rb

@@ -1,8 +1,21 @@
-
-# Time Complexity: ?
-# Space Complexity: ?
+# Time Complexity: O(n)
+# Space Complexity: O(1)
 def max_sub_array(nums)
-    return 0 if nums == nil
-
-    raise NotImplementedError, "Method not implemented yet!"
+  return 0 if nums == nil
+
+  max_so_far = 0
+  max_ending_here = 0
+
+  i = 0
+  while i < nums.length
+    max_ending_here = max_ending_here + a[i]
+    if(max_ending_here < 0)
+      max_ending_here = 0
+    elsif(max_so_far < max_ending_here)
+      max_so_far = max_ending_here
+    end
+    i+=1
+  end
+
+  return max_so_far
 end

lib/newman_conway.rb

@@ -1,7 +1,24 @@
+# Time comPlexity: O(n)
+# Space ComPlexity: O(n)
+def p(n, memo)
+  if memo[n] != nil
+    return memo[n]
+  end
+  if n == 1 || n == 2
+    result = 1
+  else
+    result = p(p(n - 1, memo), memo) + p(n - p(n - 1, memo), memo)
+  end
+  memo[n] = result
+  return result
+end
 
+def newman_conway(n)
+  if n == 0
+    raise ArgumentError
+  end
 
-# Time complexity: ?
-# Space Complexity: ?
-def newman_conway(num)
-  raise NotImplementedError, "newman_conway isn't implemented"
-end
+  memo = [nil,1]
+  p(n, memo)
+  return memo.join(" ").strip!
+end