525.3251 Merge Sorted Array

Author: Yurii-Holubchenko

525.3253.merge-sorted-array.rb

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+# https://leetcode.com/explore/learn/card/fun-with-arrays/525/inserting-items-into-an-array/3253/
+
+# Test cases:
+# nums1 = [1,2,3,0,0,0], m = 3, nums2 = [2,5,6], n = 3
+# nums1 = [1], m = 1, nums2 = [], n = 0
+# nums1 = [0], m = 0, nums2 = [1], n = 1
+# nums1 = [2,0], m = 1, nums2 = [1], n = 1
+# nums1 = [-1,0,0,3,3,3,0,0,0], m = 6, nums2 = [1,2,2], n = 3
+
+# Expected results:
+# [1,2,2,3,5,6]
+# [1]
+# [1]
+# [1,2]
+# [-1,0,0,1,2,2,3,3,3]
+
+# @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)
+  # Return nums1 of nums2 is empty
+  return nums1 if n.zero?
+
+  length = m + n
+
+  0.upto(length - 1) do |i|
+    # If nums2 is empty, then there is only elements of nums1 left
+    next if nums2.empty?
+
+    # If there is no elements left in nums1, then just copy all other elements from nums2 to nums1
+    if m.zero?
+      e = nums2.shift
+      nums1[i] = e
+    # If element from nums1 is bigger then element from nums2, then shift all elements in nums1 to the right
+    elsif nums1[i] > nums2[0]
+      e = nums2.shift
+      nums1[i + 1..length - 1] = nums1[i..length - 2]
+      nums1[i] = e
+    # If element from nums1 is smaller or equal then element from nums2, then jump to the next element
+    else
+      m -= 1
+      next
+    end
+  end
+end