Given Page requests: Reference string: $1,2,3,4,1,2,5,1,2,3,4,5$

Show the memory allocation state as the above pages are referenced, for each of the following scheduling algorithms $($given the respective number of page frames$).$ What is the number of page faults with each $?$

$1.$FIFO

Assume there are $4$ page frames of physical memory $.$

$2.$OPT

Assume there are $4$ page frames of physical memory $.$

In OPT towards the end, there can be a situation where more than one page can be evicted. In that case: use FIFO to determine which page gets evicted.

$3.$LRU

Assume there are $4$ page frames of physical memory $.$