diff --git a/problems/2026-10-19-merge-sorted-array/solution.js b/problems/2026-10-19-merge-sorted-array/solution.js
index a40861f..1797552 100644
--- a/problems/2026-10-19-merge-sorted-array/solution.js
+++ b/problems/2026-10-19-merge-sorted-array/solution.js
@@ -6,5 +6,14 @@
  * @returns {void}
  */
 export function merge(nums1, m, nums2, n) {
-  throw new Error("Not implemented");
+  let i = m - 1;
+  let j = n - 1;
+  let k = m + n - 1;
+  while (j >= 0) {
+    if (i >= 0 && nums1[i] > nums2[j]) {
+      nums1[k--] = nums1[i--];
+    } else {
+      nums1[k--] = nums2[j--];
+    }
+  }
 }