Binary Search

Binary Search: https://www.khanacademy.org/computing/computer-science/algorithms/binary-search/a/binary-search

for start + 1 < end {
    mid := (end-start)/2+start
    
    if nums[mid] > target {
        end = mid
    } else {
        start = mid
    }
}

if nums[start] == target {
    return start
} else if nums[end] == target {
    return end
}

return -1 // not within array