diff --git a/problems/2026-10-18-reverse-string/solution.js b/problems/2026-10-18-reverse-string/solution.js
index 5d57f96..71b288f 100644
--- a/problems/2026-10-18-reverse-string/solution.js
+++ b/problems/2026-10-18-reverse-string/solution.js
@@ -3,5 +3,14 @@
  * @returns {void}
  */
 export function reverseString(s) {
+  let left = 0;
+  let right = s.length - 1;
+  while (left < right) {
+    const tmp = s[left];
+    s[left] = s[right];
+    s[right] = tmp;
+    left++;
+    right--;
+  }
   throw new Error("Not implemented");
 }