092

Author: lazzzis

092/main.js

@@ -0,0 +1,64 @@
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val) {
+ *     this.val = val;
+ *     this.next = null;
+ * }
+ */
+/**
+ * @param {ListNode} head
+ * @param {number} m
+ * @param {number} n
+ * @return {ListNode}
+ */
+var reverseBetween = function(first, m, n) {
+  let pos = 0
+  const head = {
+    val: -1,
+    next: first
+  }
+  let pivot = head
+  while (pos < m - 1) {
+    pivot = pivot.next
+    pos++
+  }
+
+  const firstTail = pivot
+  const secondHead = {
+    val: -1,
+    next: pivot.next
+  }
+  pivot = pivot.next
+  pos++
+  while (pos < n) {
+    const neck = secondHead.next
+    const next = pivot.next.next
+    secondHead.next = pivot.next
+    secondHead.next.next = neck
+
+    pivot.next = next
+    pos++
+  }
+  firstTail.next = secondHead.next
+
+  return head.next
+};
+
+if (require.main === module) {
+  const head = {}
+  let pivot = head
+  for (let i = 1; i < 3; i++) {
+    pivot.val = i
+    if (i === 5) {
+      pivot.next = null
+    } else {
+      pivot.next = {}
+    }
+    pivot = pivot.next
+  }
+  pivot = reverseBetween(head, 1, 2)
+  while (pivot) {
+    console.log(pivot)
+    pivot = pivot.next
+  }
+}