diff --git a/include/s0033_search_in_rotated_sorted_array.hpp b/include/s0033_search_in_rotated_sorted_array.hpp
new file mode 100644
index 0000000..1464332
--- /dev/null
+++ b/include/s0033_search_in_rotated_sorted_array.hpp
@@ -0,0 +1,14 @@
+#ifndef S0033_SEARCH_IN_ROTATED_SORTED_ARRAY
+#define S0033_SEARCH_IN_ROTATED_SORTED_ARRAY
+
+#include <vector>
+#include <cmath>
+
+using namespace std;
+
+class Solution {
+ public:
+  int search(vector<int>& nums, int target);
+};
+
+#endif
diff --git a/src/s0033_search_in_rotated_sorted_array.cpp b/src/s0033_search_in_rotated_sorted_array.cpp
new file mode 100644
index 0000000..9d39d5c
--- /dev/null
+++ b/src/s0033_search_in_rotated_sorted_array.cpp
@@ -0,0 +1,50 @@
+#include "s0033_search_in_rotated_sorted_array.hpp"
+
+// 看到 O(logN) 的搜索算法，立马想到二分法
+// 可是二分法要求数组已排序，旋转数组又如何用二分法呢？
+// 思路很简单，对数组二分，有一半一定是有序的，另一半可能有序可能无序
+// 对有序的一半进行二分搜索，无序的部分再次进行二分，如此迭代
+
+int Solution::search(vector<int>& nums, int target) {
+  int size = nums.size();
+  int left{0};
+  int right = size - 1;
+  int mid = static_cast<int>(floor((left + right) / 2));
+  while (left <= right) {
+    mid = static_cast<int>(floor((left + right) / 2));
+    // 数组有序
+    if (nums[left] <= nums[right]) {
+      // 越界
+      if (target > nums[right] || target < nums[left]) {
+        return -1;
+      }
+      // 二分查找
+      if (nums[mid] == target) {
+        return mid;
+      } else if (nums[mid] < target) {
+        left = mid + 1;
+      } else {
+        right = mid - 1;
+      }
+    } else {  // 数组无序
+      // 左半部分有序
+      if (nums[mid] >= nums[left]) {
+        // 如果 target 在左半部分，则更新 right 然后继续迭代
+        if (target <= nums[mid] && target >= nums[left]) {
+          right = mid;
+        } else {  // target 位于右半部分或者越界
+          // 我们不在这里处理越界，因为越界的情况包含在了这个 else
+          // 语句里，继续迭代下去会出循环，然后返回 -1
+          left = mid + 1;
+        }
+      } else {  // 右半部分有序
+        if (target >= nums[mid] && target <= nums[right]) {
+          left = mid;
+        } else {
+          right = mid - 1;
+        }
+      }
+    }
+  }
+  return -1;
+}
diff --git a/tests/s0033_search_in_rotated_sorted_array.cpp b/tests/s0033_search_in_rotated_sorted_array.cpp
new file mode 100644
index 0000000..fc7b292
--- /dev/null
+++ b/tests/s0033_search_in_rotated_sorted_array.cpp
@@ -0,0 +1,27 @@
+#include "s0033_search_in_rotated_sorted_array.hpp"
+
+#include <gtest/gtest.h>
+
+TEST(Problem33, Case1) {
+  vector<int> nums{4, 5, 6, 7, 0, 1, 2};
+  int target{0};
+  int o{4};
+  Solution solution;
+  EXPECT_EQ(solution.search(nums, target), o);
+}
+
+TEST(Problem33, Case2) {
+  vector<int> nums{4, 5, 6, 7, 0, 1, 2};
+  int target{3};
+  int o{-1};
+  Solution solution;
+  EXPECT_EQ(solution.search(nums, target), o);
+}
+
+TEST(Problem33, Case3) {
+  vector<int> nums{1};
+  int target{0};
+  int o{-1};
+  Solution solution;
+  EXPECT_EQ(solution.search(nums, target), o);
+}