Binary

Homework Hack #1

def search_rotated_array(arr, target):
    left, right = 0, len(arr) - 1

    while left <= right:
        mid = (left + right) // 2

        if arr[mid] == target:
            return mid

        if arr[left] <= arr[mid]:
            if arr[left] <= target < arr[mid]:
                right = mid - 1
            else:
                left = mid + 1
        else:
            if arr[mid] < target <= arr[right]:
                left = mid + 1
            else:
                right = mid - 1

    return -1

Homework Hack #2

def find_first_and_last(arr, target):
    def find_first():
        left, right = 0, len(arr) - 1
        first = -1
        while left <= right:
            mid = (left + right) // 2
            if arr[mid] == target:
                first = mid
                right = mid - 1
            elif arr[mid] < target:
                left = mid + 1
            else:
                right = mid - 1
        return first

    def find_last():
        left, right = 0, len(arr) - 1
        last = -1
        while left <= right:
            mid = (left + right) // 2
            if arr[mid] == target:
                last = mid
                left = mid + 1
            elif arr[mid] < target:
                left = mid + 1
            else:
                right = mid - 1
        return last

    first = find_first()
    last = find_last()
    
    if first == -1:
        return -1
    return (first, last)

Homework Hack #3

def find_ceil(arr, target):
    left, right = 0, len(arr) - 1
    result = -1

    while left <= right:
        mid = (left + right) // 2

        if arr[mid] >= target:
            result = arr[mid]
            right = mid - 1
        else:
            left = mid + 1

    return result

double d = 15.7;
int i = (int)(d + 0.5);
System.out.println(i);

16