[BinarySearch][Easy] 704. Binary Search

https://leetcode.com/problems/binary-search/description/

 

 

기본적인 binary search 문제.

 

TC log(N)기반의 타 문제 풀이들의 근간이 되므로, 잘 숙지 해 둘 것.

 

int searchBS(vector<int>& nums, int left, int right, int target) 
{
    if(left > right)
        return -1;

    int mid = left + (right-left) / 2;
    if(nums[mid] == target)
        return mid;
    else if(nums[mid] < target)
        return searchBS(nums, mid+1, right, target);
    else 
        return searchBS(nums, left, mid-1, target);
}

public:
int search(vector<int>& nums, int target) 
{
    return searchBS(nums, 0, nums.size()-1, target);    
}

 

 

결과