diff --git a/153FindMinimumInRotatedSortedArray.js b/153FindMinimumInRotatedSortedArray.js
new file mode 100644
index 00000000..24ab291c
--- /dev/null
+++ b/153FindMinimumInRotatedSortedArray.js
@@ -0,0 +1,20 @@
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+var findMin = function (nums) {
+  let left = 0,
+    right = nums.length - 1;
+
+  while (left < right) {
+    let mid = (left + right) >>> 1;
+
+    if (nums[mid] > nums[right]) {
+      left = mid + 1;
+    } else {
+      right = mid;
+    }
+  }
+
+  return nums[left];
+};
diff --git a/162FindPeakElement.js b/162FindPeakElement.js
new file mode 100644
index 00000000..431da029
--- /dev/null
+++ b/162FindPeakElement.js
@@ -0,0 +1,18 @@
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+var findPeakElement = function (nums) {
+  let lo = 0,
+    hi = nums.length - 1;
+
+  while (lo < hi) {
+    let mid = lo + ((hi - lo) >>> 1);
+    if (nums[mid] < nums[mid + 1]) {
+      lo = mid + 1;
+    } else {
+      hi = mid;
+    }
+  }
+  return lo;
+};
diff --git a/34FindFirstAndLastPositionOfElementInSortedArray.js b/34FindFirstAndLastPositionOfElementInSortedArray.js
new file mode 100644
index 00000000..5f53e5b6
--- /dev/null
+++ b/34FindFirstAndLastPositionOfElementInSortedArray.js
@@ -0,0 +1,33 @@
+/**
+ * @param {number[]} nums
+ * @param {number} target
+ * @return {number[]}
+ */
+var searchRange = function (nums, target) {
+  if (nums.length === 0) return [-1, -1];
+
+  function findFirst() {
+    let lo = 0,
+      hi = nums.length - 1;
+
+    while (lo < hi) {
+      const mid = lo + ((hi - lo) >> 1); // floor
+      if (target <= nums[mid]) hi = mid;
+      else lo = mid + 1;
+    }
+    return nums[lo] === target ? lo : -1;
+  }
+
+  function findSecond() {
+    let lo = 0,
+      hi = nums.length - 1;
+
+    while (lo < hi) {
+      const mid = lo + ((hi - lo + 1) >> 1); // ceil
+      if (target >= nums[mid]) lo = mid;
+      else hi = mid - 1;
+    }
+    return nums[lo] === target ? lo : -1;
+  }
+  return [findFirst(), findSecond()];
+};