_33.cpp

cpp/Rotated Sorted Array.cpp

@@ -0,0 +1,42 @@
+class Solution {
+public:
+
+int search(vector<int>& nums, int target) 
+{
+    int n = nums.size();
+    int index = -1, left = 0, right = n-1;
+    while(left <= right)
+    {
+        int mid = left + (right - left) / 2;
+        if(mid > 0 && nums[mid] < nums[mid-1]) 
+        {
+            index = mid - 1;
+            break;
+        }
+        if(mid < n-1 && nums[mid] > nums[mid+1])
+        {
+            index = mid;
+            break;
+        }
+        if(nums[mid] > nums[right]) left = mid + 1;
+        else right = mid - 1;
+    }
+    left = 0, right = index;
+    while(left <= right)
+    {
+        int mid = left + (right - left) / 2;
+        if(nums[mid] == target) return mid;
+        else if(nums[mid] > target) right = mid-1;
+        else left = mid + 1;
+    }
+    left = index + 1, right = n - 1;
+    while(left <= right)
+    {
+        int mid = left + (right - left) / 2;
+        if(nums[mid] == target) return mid;
+        else if(nums[mid] > target) right = mid - 1;
+        else left = mid + 1;
+    }
+    return -1;
+}
+};