PWC 339: add ch-2 in Elixir

1 files changed, 102 insertions, 0 deletions

diff --git a/challenge-339/spadacciniweb/elixir/ch-2.exs b/challenge-339/spadacciniweb/elixir/ch-2.exs
new file mode 100644
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+++ b/challenge-339/spadacciniweb/elixir/ch-2.exs
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+# Task 2: Peak Point
+# Submitted by: Mohammad Sajid Anwar
+# You are given an array of altitude gain.
+# Write a script to find the peak point gained.
+# 
+# Example 1
+# Input: @gain = (-5, 1, 5, -9, 2)
+# Output: 1
+# 
+# start: 0
+# 1st change:  0 + (-5) = -5
+# 2nd change: -5 + 1    = -4
+# 3rd change: -4 + 5    = 1
+# 4th change:  1 + (-9) = -8
+# 5th change: -8 + 2    = -6
+# 
+# max(0, -5, -4, 1, -8, -6) = 1
+# 
+# Example 2
+# Input: @gain = (10, 10, 10, -25)
+# Output: 30
+# 
+# start: 0
+# 1st change:  0 + 10    = 10
+# 2nd change: 10 + 10    = 20
+# 3rd change: 20 + 10    = 30
+# 4th change: 30 + (-25) = 5
+# 
+# max(0, 10, 20, 30, 5) = 30
+# 
+# Example 3
+# Input: @gain = (3, -4, 2, 5, -6, 1)
+# Output: 6
+# 
+# start: 0
+# 1st change:  0 + 3    = 3
+# 2nd change:  3 + (-4) = -1
+# 3rd change: -1 + 2    = 1
+# 4th change:  1 + 5    = 6
+# 5th change:  6 + (-6) = 0
+# 6th change:  0 + 1    = 1
+# 
+# max(0, 3, -1, 1, 6, 0, 1) = 6
+# 
+# Example 4
+# Input: @gain = (-1, -2, -3, -4)
+# Output: 0
+# 
+# start: 0
+# 1st change:  0 + (-1) = -1
+# 2nd change: -1 + (-2) = -3
+# 3rd change: -3 + (-3) = -6
+# 4th change: -6 + (-4) = -10
+# 
+# max(0, -1, -3, -6, -10) = 0
+# 
+# Example 5
+# Input: @gain = (-10, 15, 5)
+# Output: 10
+# 
+# start: 0
+# 1st change:   0 + (-10) = -10
+# 2nd change: -10 + 15    = 5
+# 3rd change:   5 + 5     = 10
+# 
+# max(0, -10, 5, 10) = 10
+
+defmodule Peak do
+
+  def get_gains([head | tail], acc) do
+    [acc | get_gains(tail, head + acc) ]
+  end
+
+  def get_gains([], acc) do
+    [acc]
+  end
+
+  def get_peak(gains) do
+    Enum.max( get_gains(gains, 0) )
+  end
+
+  def out(gains) do
+    IO.write( "(" <> Enum.join(gains, ",") <> ") -> ")
+    IO.puts( get_peak(gains) )
+  end
+
+end
+
+gains = [-5, 1, 5, -9, 2]
+Peak.out(gains)
+
+gains = [10, 10, 10, -25]
+Peak.out(gains)
+
+gains = [3, -4, 2, 5, -6, 1]
+Peak.out(gains)
+
+gains = [-1, -2, -3, -4]
+Peak.out(gains)
+
+gains = [-10, 15, 5]
+Peak.out(gains)