Create 2095-delete-the-middle-node-of-a-linked-list.js

Author: everthis

2095-delete-the-middle-node-of-a-linked-list.js

@@ -0,0 +1,36 @@
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val, next) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.next = (next===undefined ? null : next)
+ * }
+ */
+/**
+ * @param {ListNode} head
+ * @return {ListNode}
+ */
+const deleteMiddle = function(head) {
+  if(head == null) return head
+  const dummy = new ListNode(null, head)
+  let n = 0, cur = head
+  while(cur) {
+    n++
+    cur = cur.next
+  }
+  if(n === 1) return null
+  const mid = Math.floor(n / 2)
+  cur = dummy.next
+  let pre = dummy 
+  for(let i = 0; i < n; i++) {
+    if(i === mid - 1) {
+      pre = cur
+      // pre.next = cur.next.next
+    }
+    if(i === mid) {
+      pre.next = cur.next
+    }
+    if(i > mid) break
+    cur = cur.next
+  }
+  return dummy.next
+};