static bool randomChanceSeemsReasonable(double p) {
int i, hits;
double expected;
hits = 0;
for (i = 0; i < N_TRIALS; i++) {
if (randomChance(p)) hits++;
}
expected = p * N_TRIALS;
if (hits < 0.5 * expected || (p == 1.0 && hits != N_TRIALS)) {
reportError("Hit count low");
return false;
} else if (hits > 1.5 * expected || (p == 0.0 && hits != 0)) {
reportError("Hit count high");
return false;
}
return true;
}
/*
* Function: RunSimulation
* Usage: RunSimulation();
* -----------------------
* This function runs the actual simulation. In each time unit,
* the program first checks to see whether a new customer arrives.
* Then, if the cashier is busy (indicated by a nonzero value for
* serviceTimeRemaining), the program decrements that variable to
* indicate that one more time unit has passed. Finally, if the
* cashier is free, the simulation serves another customer from
* the queue after recording the waiting time for that customer.
*/
void runSimulation() {
Queue<int> queue;
int serviceTimeRemaining = 0;
int nServed = 0;
long totalWait = 0;
long totalLength = 0;
for (int t = 0; t < SIMULATION_TIME; t++) {
if (randomChance(ARRIVAL_PROBABILITY)) {
queue.enqueue(t);
}
if (serviceTimeRemaining > 0) {
serviceTimeRemaining--;
if (serviceTimeRemaining == 0) nServed++;
} else if (!queue.isEmpty()) {
totalWait += t - queue.dequeue();
serviceTimeRemaining = randomInteger(MIN_SERVICE_TIME, MAX_SERVICE_TIME);
}
totalLength += queue.size();
}
reportResults(nServed, totalWait, totalLength);
}
