✨ [23] Merge sort attempt

Author: enkr1

23/my_solution.js

@@ -1,18 +1,92 @@
-function ListNode(val, next) {
-  this.val = (val === undefined ? 0 : val)
-  this.next = (next === undefined ? null : next)
+class ListNode {
+  constructor(val, next) {
+    this.val = (val === undefined ? 0 : val)
+    this.next = (next === undefined ? null : next)
+  }
 }
 
 /**
  * @param {ListNode[]} lists
  * @return {ListNode}
  */
-var mergeKLists = (lists) => {
-  console.log("lists")
-  console.log(lists)
+const mergeKLists = (lists) => {
+  if (0 === lists.length) return null;
+  // if (1 === lists.length) return lists;
 
-  return;
+  while (lists.length > 1) {
+    lists.push(mergetTwoLists(lists.shift(), lists.shift()));
+  }
+  // while (lists.length > 1) {
+  //   console.log("___")
+  //   console.log(lists)
+  //   let mergedLists = mergetTwoLists(lists.shift(), lists.shift())
+  //   lists.push(mergedLists);
+  // }
+
+  console.log("result")
+  console.log(lists[0])
 
+  return;
 };
 
+
+const mergetTwoLists = (ll1, ll2) => {
+  let dummy = new ListNode(), head = dummy;
+  while (ll1 && ll2) {
+    console.log(`ll1.val:${ll1.val}, ll2.val:${ll2.val}`)
+    if (ll1.val <= ll2.val) {
+      dummy.next = ll1;
+      ll1 = ll1.next
+    } else {
+      dummy.next = ll2;
+      ll2 = ll2.next
+    }
+
+    dummy = dummy.next;
+
+    // edge case
+    // console.log("result")
+    // console.log(result)
+    // console.log("ll1")
+    // console.log(ll1)
+    // console.log("ll2")
+    // console.log(ll2)
+  }
+
+  // console.log("ll1")
+  // console.log(ll1)
+  // console.log(ll1 === null)
+  // console.log("ll2")
+  // console.log(ll2)
+  // console.log(ll2 === null)
+  //
+  if (null === ll2) {
+    console.log("Hereeeee")
+    dummy.next = ll1;
+  } else {
+    dummy.next = ll2;
+  }
+
+  return head.next;
+}
+
+
 // [[1,4,5],[1,3,4],[2,6]]
+// mergeKLists([
+//   new ListNode(1,
+//     new ListNode(4,
+//       new ListNode(5))),
+//   new ListNode(1,
+//     new ListNode(3,
+//       new ListNode(4))),
+//   new ListNode(2,
+//     new ListNode(6))
+// ])
+
+// mergeKLists([
+//   new ListNode(1,
+//     new ListNode(4,
+//       new ListNode(5)))
+// ])
+
+mergeKLists([])

23/solution.js

@@ -0,0 +1,40 @@
+class ListNode {
+  constructor(val, next) {
+    this.val = (val === undefined ? 0 : val)
+    this.next = (next === undefined ? null : next)
+  }
+}
+
+/**
+ * @param {ListNode[]} lists
+ * @return {ListNode}
+ */
+const mergeKLists = (lists) => {
+  if (0 === lists.length) return null;
+
+  while (lists.length > 1) {
+    lists.push(mergetTwoLists(lists.shift(), lists.shift()));
+  }
+
+  return lists[0];
+};
+
+
+const mergetTwoLists = (ll1, ll2) => {
+  let dummy = new ListNode(), head = dummy;
+  while (ll1 && ll2) {
+    if (ll1.val <= ll2.val) {
+      dummy.next = ll1;
+      ll1 = ll1.next
+    } else {
+      dummy.next = ll2;
+      ll2 = ll2.next
+    }
+
+    dummy = dummy.next;
+  }
+
+  dummy.next = (null === ll2) ? ll1 : ll2;
+
+  return head.next;
+}