ef find_last_one(arr):
    low, high = 0, len(arr) - 1
    result = -1  # Initialize result to -1, in case there are no 1s in the array

    while low <= high:
        mid = (low + high) // 2

        if arr[mid] == 1:
            result = mid  # Update the result and continue searching on the right side
            low = mid + 1
        else:
            high = mid - 1  # Search on the left side

    return result


# Example usage
arr = []
for i in range(11):
    arr.append(1)
for i in range(11, 22):
    arr.append(0)

index_of_last_one = find_last_one(arr)

print("Index of the last occurrence of 1:", index_of_last_one)


def find_first_one(arr):
    low, high = 0, len(arr) - 1
    result = -1  # Initialize result to -1, in case there are no 1s in the array

    while low <= high:
        mid = (low + high) // 2

        if arr[mid] == 1:
            result = mid  # Update the result and continue searching on the left side
            high = mid - 1
        else:
            low = mid + 1  # Search on the right side

    return result


# Example usage
arr = arr[::-1]
index_of_first_one = find_first_one(arr)

print("Index of the first occurrence of 1:", index_of_first_one)