diff --git a/sik9252/BinarySearch.js b/sik9252/BinarySearch.js
new file mode 100644
index 0000000..7646588
--- /dev/null
+++ b/sik9252/BinarySearch.js
@@ -0,0 +1,25 @@
+/**
+ * @param {number[]} nums
+ * @param {number} target
+ * @return {number}
+ */
+var search = function (nums, target) {
+  let left = 0;
+  let right = nums.length - 1;
+
+  while (left <= right) {
+    const mid = Math.floor((left + right) / 2);
+
+    if (nums[mid] === target) {
+      return mid;
+    }
+
+    if (nums[mid] < target) {
+      left = mid + 1;
+    } else {
+      right = mid - 1;
+    }
+  }
+
+  return -1;
+};
diff --git a/sik9252/FloodFill.js b/sik9252/FloodFill.js
new file mode 100644
index 0000000..7cb5e82
--- /dev/null
+++ b/sik9252/FloodFill.js
@@ -0,0 +1,28 @@
+var floodFill = function (image, sr, sc, color) {
+  const startColor = image[sr][sc];
+  if (startColor === color) return image;
+
+  const dx = [-1, 1, 0, 0];
+  const dy = [0, 0, -1, 1];
+  const row = image.length;
+  const col = image[0].length;
+
+  const queue = [[sr, sc]];
+  image[sr][sc] = color;
+
+  while (queue.length) {
+    const [x, y] = queue.shift();
+
+    for (let i = 0; i < 4; i++) {
+      const nx = x + dx[i];
+      const ny = y + dy[i];
+
+      if (nx >= 0 && nx < row && ny >= 0 && ny < col && image[nx][ny] === startColor) {
+        image[nx][ny] = color;
+        queue.push([nx, ny]);
+      }
+    }
+  }
+
+  return image;
+};
diff --git a/sik9252/InvertBinaryTree.js b/sik9252/InvertBinaryTree.js
new file mode 100644
index 0000000..92b6e54
--- /dev/null
+++ b/sik9252/InvertBinaryTree.js
@@ -0,0 +1,10 @@
+var invertTree = function (root) {
+  if (root === null) return null;
+
+  [root.left, root.right] = [root.right, root.left];
+
+  invertTree(root.left);
+  invertTree(root.right);
+
+  return root;
+};
diff --git a/sik9252/ValidAnagram.js b/sik9252/ValidAnagram.js
new file mode 100644
index 0000000..0dc2686
--- /dev/null
+++ b/sik9252/ValidAnagram.js
@@ -0,0 +1,16 @@
+var isAnagram = function (s, t) {
+  if (s.length !== t.length) return false;
+
+  const map = new Map();
+
+  for (let i = 0; i < s.length; i++) {
+    map.set(s[i], (map.get(s[i]) || 0) + 1);
+    map.set(t[i], (map.get(t[i]) || 0) - 1);
+  }
+
+  for (const value of map.values()) {
+    if (value !== 0) return false;
+  }
+
+  return true;
+};