01 Binary search.cpp

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