A system has $n$ resources $R_0, \dots,R_{n-1}$, and $k$ processes $P_0, \dots, P_{k-1}$. The implementation of the resource request logic of each process $P_i$ is as follows:
if(i%2==0){
if(i<n) request Ri;
if(i+2<n) request Ri+2;
}
else{
if(i<n) request Rn−i;
if(i+2<n) request Rn−i−2;
}
In which of the following situations is a deadlock possible?
- $n=40,\: k=26$
- $n=21,\:k=12$
- $n=20,\:k=10$
- $n=41,\:k=19$
