1
Imprecise descriptions of circular queue operations — omitting the empty-queue check
“many answers showing some understanding of the process of removing an item from a circular queue but lacking the precision required to get many marks”— 7517/1 Paper 1, June 2022
How to fix: For circular queue deletion: state the pointer arithmetic explicitly (rear-pointer wraps using modulo), check for an empty queue (front == rear or a count variable == 0) BEFORE attempting deletion, increment the front pointer after removal, and make clear that items do not physically shift. Describe a linear queue only when specifically asked — switching models loses marks.