An automated municipal lighting system controls a street with 7 smart lamps, indexed 0 to 6.

The subroutines in the table below are used to manage the states of the lamps, switching them between ON and OFF.

Subroutine	Explanation
`INVERT(n)`	If the lamp at index $n\,$ is `ON` it is set to `OFF`. If it is `OFF` it is set to `ON`.
`MIRROR(n)`	The lamp at index $n\,$ is set to the same state as the lamp at index $n + 1$ .
`EXTINGUISH_BETWEEN(m, n)`	All lamps strictly between index $m\,$ and index $n$ (but not including $m\,$ and $n$ ) are set to `OFF`.

If the starting array of lamps is:

0	1	2	3	4	5	6
ON	ON	ON	ON	ON	ON	ON

Write an algorithm, using exactly three subroutine calls, that means the final array of lamps will be:

0	1	2	3	4	5	6
OFF	OFF	OFF	OFF	OFF	OFF	OFF

You must use each of the subroutines INVERT, MIRROR and EXTINGUISH_BETWEEN exactly once in your answer.

An automated municipal lighting system controls a street with 7 smart lamps, indexed 0 to 6.

The subroutines in the table below are used to manage the states of the lamps, switching them between ON and OFF.

Subroutine	Explanation
`INVERT(n)`	If the lamp at index $n\,$ is `ON` it is set to `OFF`. If it is `OFF` it is set to `ON`.
`MIRROR(n)`	The lamp at index $n\,$ is set to the same state as the lamp at index $n + 1$ .
`EXTINGUISH_BETWEEN(m, n)`	All lamps strictly between index $m\,$ and index $n$ (but not including $m\,$ and $n$ ) are set to `OFF`.

If the starting array of lamps is:

0	1	2	3	4	5	6
ON	ON	ON	ON	ON	ON	ON

Write an algorithm, using exactly three subroutine calls, that means the final array of lamps will be:

0	1	2	3	4	5	6
OFF	OFF	OFF	OFF	OFF	OFF	OFF

You must use each of the subroutines INVERT, MIRROR and EXTINGUISH_BETWEEN exactly once in your answer.

Representing algorithms

Representing algorithms Questions