Integer listSize is read from input, then listSize integers are read from input and stored in ArrayList tokensToPick. In

makesequence$(),$ complete the recursive case to perform the following tasks:

Move the element at index i of remainTokens to the end of pickedTokens.

Recursively call makeSequence$().$

Move the element from the end of pickedTokens back to index i of remainTokens.

Click here for example

Ex: If the input is:

$3$

$41720$

then the output is:

All unique sequences $of2$:

$4+17=21$

$4+20=24$

$17+4=21$

$17+20=37$

$20+4=24$

$20+17=37$

Note:

ArrayList.remove $($i$)$ removes the element at index i of ArrayList.

ArrayList.add $($i$,$ x$)$ adds x into ArrayList at index i$.$