# 8. 33. Search in Rotated Sorted Array

**33. Search in Rotated Sorted Array**

**Medium**

22.1K

1.3K

Companies

There is an integer array `nums` sorted in ascending order (with **distinct** values).

Prior to being passed to your function, `nums` is **possibly rotated** at an unknown pivot index `k` (`1 <= k < nums.length`) such that the resulting array is `[nums[k], nums[k+1], ..., nums[n-1], nums[0], nums[1], ..., nums[k-1]]` (**0-indexed**). For example, `[0,1,2,4,5,6,7]` might be rotated at pivot index `3` and become `[4,5,6,7,0,1,2]`.

Given the array `nums` **after** the possible rotation and an integer `target`, return *the index of* `target` *if it is in* `nums`*, or* `-1` *if it is not in* `nums`.

You must write an algorithm with `O(log n)` runtime complexity.

**Example 1:**

```
Input: nums = [4,5,6,7,0,1,2], target = 0
Output: 4

```

**Example 2:**

```
Input: nums = [4,5,6,7,0,1,2], target = 3
Output: -1

```

**Example 3:**

```
Input: nums = [1], target = 0
Output: -1

```

**Constraints:**

* `1 <= nums.length <= 5000`
* `104 <= nums[i] <= 104`
* All values of `nums` are **unique**.
* `nums` is an ascending array that is possibly rotated.
* `104 <= target <= 104`

{% embed url="<https://leetcode.com/problems/search-in-rotated-sorted-array/description/>" %}

> time: O(n)

> space: O(1)

```jsx
/**
 * @param {number[]} nums
 * @param {number} target
 * @return {number}
 */
var search = function(nums, target) {
    
    let s = 0;
    let e = nums.length - 1;
    while (s < e) {
        const m = s + Math.floor((e - s) / 2);
        if (nums[m] <= nums[e]) {
            e = m;
        } else {
            s = m + 1;
        }
    }

    const pivot = e;
    if (nums[pivot] <= target && target <= nums[nums.length - 1]) {
        s = pivot - 1;
        e = nums.length;
    } else {
        s = -1;
        e = pivot;
    }
    // 0,1,2,2,2,3,4,5,6
    while (s + 1 < e) {
        const m = s + Math.floor((e - s) / 2);
        if (target <= nums[m]) {
            e = m;
        } else {
            s = m;
        }
    }

    return nums[e] === target ? e : -1;
};
```