From 291b5be8094abb5c2d971d1421a5e7b56862e624 Mon Sep 17 00:00:00 2001
From: "Ahmed M. Abd EL-latif" <ahmed.abdelatife@gmail.com>
Date: Fri, 10 Jun 2022 18:00:46 +0200
Subject: [PATCH] 70 && 83 && 88

---
 Climbing_Stairs.rb                           | 37 ++++++++++++++++++++
 Merge_Sorted_Array.rb                        | 24 +++++++++++++
 Remove_Duplicates_from_Sorted_Linked_List.rb | 13 +++++++
 3 files changed, 74 insertions(+)
 create mode 100644 Climbing_Stairs.rb
 create mode 100644 Merge_Sorted_Array.rb
 create mode 100644 Remove_Duplicates_from_Sorted_Linked_List.rb

diff --git a/Climbing_Stairs.rb b/Climbing_Stairs.rb
new file mode 100644
index 0000000..985907b
--- /dev/null
+++ b/Climbing_Stairs.rb
@@ -0,0 +1,37 @@
+#
+# @lc app=leetcode id=70 lang=ruby
+#
+# [70] Climbing Stairs
+#
+# https://leetcode.com/problems/climbing-stairs/description/
+#
+# You are climbing a stair case. It takes n steps to reach to the top.
+#
+# Each time you can either climb 1 or 2 steps. In how many distinct
+# ways can you climb to the top?
+#
+# Note: Given n will be a positive integer.
+#
+# Example 1:
+#
+# Input: 2
+# Output: 2
+# Explanation: There are two ways to climb to the top.
+# 1. 1 step + 1 step
+# 2. 2 steps
+#
+# Example 2:
+#
+# Input: 3
+# Output: 3
+# Explanation: There are three ways to climb to the top.
+# 1. 1 step + 1 step + 1 step
+# 2. 1 step + 2 steps
+# 3. 2 steps + 1 step
+
+
+# @param {Integer} n
+# @return {Integer}
+def climb_stairs(n)
+  Hash.new { |h, k| h[k] = h[k-1] + h[k-2] }.merge({1=>1, 2=>2})[n]
+end
\ No newline at end of file
diff --git a/Merge_Sorted_Array.rb b/Merge_Sorted_Array.rb
new file mode 100644
index 0000000..ab61146
--- /dev/null
+++ b/Merge_Sorted_Array.rb
@@ -0,0 +1,24 @@
+# @param {Integer[]} nums1
+# @param {Integer} m
+# @param {Integer[]} nums2
+# @param {Integer} n
+# @return {Void} Do not return anything, modify nums1 in-place instead.
+def merge(nums1, m, nums2, n)
+    i, j, k = n - 1, m - 1, nums1.size - 1
+    
+    while i >= 0
+        if j < 0
+            nums1[k] = nums2[i]
+            i -= 1
+        elsif nums1[j] > nums2[i]
+            nums1[k] = nums1[j]
+            j -= 1
+        else
+            nums1[k] = nums2[i]
+            i -= 1
+        end   
+        k -= 1
+    end
+	
+    nums1
+end
\ No newline at end of file
diff --git a/Remove_Duplicates_from_Sorted_Linked_List.rb b/Remove_Duplicates_from_Sorted_Linked_List.rb
new file mode 100644
index 0000000..1c7c7c9
--- /dev/null
+++ b/Remove_Duplicates_from_Sorted_Linked_List.rb
@@ -0,0 +1,13 @@
+def delete_duplicates(head)
+    cursor = head
+
+  while cursor and cursor.next
+    if cursor.next.val == cursor.val
+      cursor.next = cursor.next.next
+    else
+      cursor = cursor.next
+    end
+  end
+
+  head
+end
\ No newline at end of file