Data commit

Task/Greatest-subsequential-sum/Elixir/greatest-subsequential-sum-1.elixir

@@ -0,0 +1,17 @@
+defmodule Greatest do
+  def subseq_sum(list) do
+    list_i = Enum.with_index(list)
+    acc = {0, 0, length(list), 0, 0}
+    {_,max,first,last,_} = Enum.reduce(list_i, acc, fn {elm,i},{curr,max,first,last,curr_first} ->
+      if curr < 0 do
+        if elm > max, do: {elm, elm, i,     i,    curr_first},
+                    else: {elm, max, first, last, curr_first}
+      else
+        cur2 = curr + elm
+        if cur2 > max, do: {cur2, cur2, curr_first, i, curr_first},
+                     else: {cur2, max,  first,   last, curr_first}
+      end
+    end)
+    {max, Enum.slice(list, first..last)}
+  end
+end

Task/Greatest-subsequential-sum/Elixir/greatest-subsequential-sum-2.elixir

@@ -0,0 +1,11 @@
+defmodule Greatest do
+  def subseq_sum(list) do
+    limit = length(list) - 1
+    ij = for i <- 0..limit, j <- i..limit, do: {i,j}
+    Enum.reduce(ij, {0, []}, fn {i,j},{max, subseq} ->
+      slice = Enum.slice(list, i..j)
+      sum = Enum.sum(slice)
+      if sum > max, do: {sum, slice}, else: {max, subseq}
+    end)
+  end
+end

Task/Greatest-subsequential-sum/Elixir/greatest-subsequential-sum-3.elixir

@@ -0,0 +1,9 @@
+data = [ [1, 2, 3, 4, 5, -8, -9, -20, 40, 25, -5],
+         [-1, -2, 3, 5, 6, -2, -1, 4, -4, 2, -1],
+         [-1, -2, -3, -4, -5],
+         [] ]
+Enum.each(data, fn input ->
+  IO.puts "\nInput seq: #{inspect input}"
+  {max, subseq} = Greatest.subseq_sum(input)
+  IO.puts "  Max sum: #{max}\n   Subseq: #{inspect subseq}"
+end)