feat: 两数相加 II

Author: sl1673495

链表/两数相加 II-445.js

@@ -0,0 +1,69 @@
+var reverseList = function (head) {
+  if (!head) return null
+  let res = null
+  let dfs = function (node) {
+      if (node.next) {
+          dfs(node.next)
+          node.next.next = node
+      } else {
+          res = node
+      }
+  }
+
+  dfs(head)
+
+  head.next = null
+
+  return res
+};
+
+var addTwoNumbers = function (l1, l2) {
+  l1 = reverseList(l1)
+  l2 = reverseList(l2)
+
+  let i = 0
+  let root = new ListNode()
+  let cur = root
+  let plus = false
+
+  let traverse = (node1, node2) => {
+      let isDouble = !!node2
+      while (isDouble ? (node1 && node2) : node1) {
+          cur.next = new ListNode()
+          cur = cur.next
+
+          let sum = node1.val + (plus ? 1 : 0)
+          if (isDouble) {
+              sum += node2.val
+          }
+
+          if (sum >= 10) {
+              sum %= 10
+              plus = true
+          } else {
+              plus = false
+          }
+          cur.val = sum
+
+          node1 = node1.next
+          if (isDouble) {
+              node2 = node2.next
+          }
+      }
+
+      if (node1) {
+          traverse(node1)
+      }
+      if (node2) {
+          traverse(node2)
+      }
+  }
+
+  traverse(l1, l2)
+
+  if (plus) {
+      cur.next = new ListNode(1)
+  }
+
+  return reverseList(root.next)
+};