diff --git a/HamSungJun/LinkedList/Solution_1290.ts b/HamSungJun/LinkedList/Solution_1290.ts
new file mode 100644
index 0000000..67ac145
--- /dev/null
+++ b/HamSungJun/LinkedList/Solution_1290.ts
@@ -0,0 +1,19 @@
+function getDecimalValue (head: ListNode | null): number {
+  let isOneBitOccurred = false
+  let out = ''
+  let temp = head
+  while (temp !== null) {
+    if (temp.val === 1) {
+      isOneBitOccurred = true
+      out += '1'
+    } else if (temp.val === 0 && isOneBitOccurred) {
+      out += '0'
+    }
+    temp = temp.next
+  }
+  let acc = 0
+  for (let i = 0; i < out.length; i++) {
+    acc += (2 ** (out.length - 1 - i)) * parseInt(out[i])
+  }
+  return acc
+};
diff --git a/HamSungJun/LinkedList/Solution_237.ts b/HamSungJun/LinkedList/Solution_237.ts
new file mode 100644
index 0000000..bf5bccf
--- /dev/null
+++ b/HamSungJun/LinkedList/Solution_237.ts
@@ -0,0 +1,19 @@
+/**
+ * Definition for singly-linked list.
+ * class ListNode {
+ *     val: number
+ *     next: ListNode | null
+ *     constructor(val?: number, next?: ListNode | null) {
+ *         this.val = (val===undefined ? 0 : val)
+ *         this.next = (next===undefined ? null : next)
+ *     }
+ * }
+ */
+
+/**
+ Do not return anything, modify it in-place instead.
+ */
+function deleteNode (root: ListNode | null): void {
+  root.val = root.next.val
+  root.next = root.next.next
+};
diff --git a/HamSungJun/LinkedList/Solution_876.ts b/HamSungJun/LinkedList/Solution_876.ts
new file mode 100644
index 0000000..b598dd2
--- /dev/null
+++ b/HamSungJun/LinkedList/Solution_876.ts
@@ -0,0 +1,29 @@
+/**
+ * Definition for singly-linked list.
+ * class ListNode {
+ *     val: number
+ *     next: ListNode | null
+ *     constructor(val?: number, next?: ListNode | null) {
+ *         this.val = (val===undefined ? 0 : val)
+ *         this.next = (next===undefined ? null : next)
+ *     }
+ * }
+ */
+
+function middleNode (head: ListNode | null): ListNode | null {
+  let lenList = 1
+  let temp = head
+  while (temp.next !== null) {
+    temp = temp.next
+    lenList += 1
+  }
+
+  temp = head
+  const mid = (lenList % 2 !== 0) ? Math.ceil(lenList / 2) : (lenList / 2) + 1
+  let count = 1
+  while (count < mid) {
+    temp = temp.next
+    count += 1
+  }
+  return temp
+};