# leetcode\_704

## Given a sorted (in ascending order) integer array nums of n elements and a target value, write a function to search target in nums. If target exists, then return its index, otherwise return -1.

```
Example 1:

Input: nums = [-1,0,3,5,9,12], target = 9
Output: 4
Explanation: 9 exists in nums and its index is 4

Example 2:

Input: nums = [-1,0,3,5,9,12], target = 2
Output: -1
Explanation: 2 does not exist in nums so return -1
```

## Note:

* You may assume that all elements in nums are unique.

  n will be in the range \[1, 10000].
* The value of each element in nums will be in the range \[-9999, 9999].

## Solutions

1. **straight forward**

```cpp
class Solution {
public:
    int search(vector<int>& nums, int target) {
        int lo = 0, hi = nums.size() - 1;
        while (lo < hi) {
            int mid = lo + ((hi - lo) / 2);
            if (target > nums[mid])
                lo = mid + 1;
            else
                hi = mid;
        }
        return nums[lo] == target ? lo : -1;
    }
};
```