in this program,
p , q,r are taking values a,++a,a++ respectivally .
++a means first increase the value of a ,then use
a++ means first use value of a then increase
thus r=5 then increase value by 1. a=6 now
q=7 b/c value is increase first by 1 means a=6+1 =7 then use/assign.
ais updated now 7 in memory so p=7.