Circular queue operations

Implement and exercise a fixed-capacity circular queue (ring buffer). You are given a capacity and a list of operations; each operation is a list whose first element is the op name. Supported ops: ['enQueue', x] inserts x at the rear and returns True, or False if full; ['deQueue'] removes the front and returns True, or False if empty; ['Front'] returns the front value or -1 if empty; ['Rear'] returns the rear value or -1 if empty; ['isEmpty'] returns a bool; ['isFull'] returns a bool. Return the list of results, one per operation, in order. There are 1 to 3000 operations and capacity is between 1 and 1000.