diff --git a/src/0080/index.test.ts b/src/0080/index.test.ts
index e6d5ef5..9800d68 100644
--- a/src/0080/index.test.ts
+++ b/src/0080/index.test.ts
@@ -1,4 +1,4 @@
-import { merge } from '.';
+import { removeDuplicates } from '.';
 
 describe('80. Remove Duplicates from Sorted Array II', () => {
   interface TestCase {
@@ -33,7 +33,7 @@ describe('80. Remove Duplicates from Sorted Array II', () => {
   test.each(testCases)(
     'Case %#',
     ({ input: { nums }, output: { n, expected } }) => {
-      const result = merge(nums);
+      const result = removeDuplicates(nums);
       expect(result).toBe(n);
       for (let i = 0; i < result; i++) {
         expect(nums[i]).toBe(expected[i]);
diff --git a/src/0080/index.ts b/src/0080/index.ts
index 6c90b4b..0c06f3d 100644
--- a/src/0080/index.ts
+++ b/src/0080/index.ts
@@ -1,3 +1,11 @@
-function removeDuplicates(nums: number[]): number {}
+function removeDuplicates(nums: number[]): number {
+  let i = 0;
+  for (const n of nums) {
+    if (i < 2 || n > nums[i - 2]) {
+      nums[i++] = n;
+    }
+  }
+  return i;
+}
 
 export { removeDuplicates };