Leetcode: Swap Nodes In Pairs - Qiita

require 'minitest/autorun' require 'pry' class SwapNodesInPairs < Minitest::Test def test_run list = ListNode.new(1) list.next = ListNode.new(2) list.next.next = ListNode.new(3) list.next.next.next = ListNode.new(4) new_list = swap_pairs(list) assert_equal(2, new_list.val) assert_equal(1, new_list.next.val) assert_equal(4, new_list.next.next.val) assert_equal(3, new_list.next.next.next.val) list =