Add Search in rotated sorted array in C++

C++/Search_in_rotated_sorted_array.cpp

@@ -0,0 +1,112 @@
+#include <iostream>
+#include <vector>
+using namespace std;
+
+class Solution {
+public:
+    int search(vector<int>& nums, int target) {
+        int n = nums.size();
+
+        // Edge case: if the array has only two elements
+        if (n == 2) {
+            if (target == nums[0]) return 0;
+            else if (target == nums[1]) return 1;
+            else return -1;
+        }
+
+        // Find the pivot point where the rotation happens
+        int lo = 0;
+        int hi = n - 1;
+        int pivot = -1;
+
+        while (lo <= hi) {
+            int mid = lo + (hi - lo) / 2;
+
+            // Check if we are at the beginning or end of the array
+            if (mid == 0) lo = mid + 1;
+            else if (mid == n - 1) hi = mid - 1;
+
+            // Check if mid is the pivot point
+            else if (nums[mid] < nums[mid + 1] && nums[mid] < nums[mid - 1]) {
+                pivot = mid;
+                break;
+            }
+            else if (nums[mid] > nums[mid + 1] && nums[mid] > nums[mid - 1]) {
+                pivot = mid + 1;
+                break;
+            }
+
+            // Adjust the search range
+            else if (nums[mid] > nums[hi]) {
+                lo = mid + 1;
+            } else {
+                hi = mid - 1;
+            }
+        }
+
+        // If no pivot was found, perform normal binary search
+        if (pivot == -1) {
+            lo = 0;
+            hi = n - 1;
+            while (lo <= hi) {
+                int mid = lo + (hi - lo) / 2;
+                if (nums[mid] == target) {
+                    return mid;
+                } else if (nums[mid] > target) {
+                    hi = mid - 1;
+                } else {
+                    lo = mid + 1;
+                }
+            }
+            return -1;
+        }
+
+        // Binary search in the left half
+        if (target >= nums[0] && target <= nums[pivot - 1]) {
+            lo = 0;
+            hi = pivot - 1;
+            while (lo <= hi) {
+                int mid = lo + (hi - lo) / 2;
+                if (nums[mid] == target) {
+                    return mid;
+                } else if (nums[mid] > target) {
+                    hi = mid - 1;
+                } else {
+                    lo = mid + 1;
+                }
+            }
+        }
+        // Binary search in the right half
+        else {
+            lo = pivot;
+            hi = n - 1;
+            while (lo <= hi) {
+                int mid = lo + (hi - lo) / 2;
+                if (nums[mid] == target) {
+                    return mid;
+                } else if (nums[mid] > target) {
+                    hi = mid - 1;
+                } else {
+                    lo = mid + 1;
+                }
+            }
+        }
+
+        return -1;
+    }
+};
+
+int main() {
+    Solution sol;
+    vector<int> nums = {4, 5, 6, 7, 0, 1, 2};
+    int target = 0;
+
+    int result = sol.search(nums, target);
+    if (result != -1) {
+        cout << "Target " << target << " found at index: " << result << endl;
+    } else {
+        cout << "Target " << target << " not found in the array." << endl;
+    }
+
+    return 0;
+}