Build a Festival Crowd Flow Simulator - Step 30

JavaScript
1

Tell us what’s happening:

Is there anything wrong with my code or is it that this is a bug?

Your code so far

const morningGates = [
  { id: "North", capacity: 5, queue: [3, 6, 2, 4] },
  { id: "East", capacity: 3, queue: [2, 4, 3, 5] },
  { id: "South", capacity: 4, queue: [1, 2, 3, 1] },
  { id: "West", capacity: 2, queue: [4, 1, 2, 3] },
];

const nightGates = [
  { id: "North", capacity: 4, queue: [6, 2, 5, 1] },
  { id: "East", capacity: 2, queue: [3, 3, 4, 2] },
  { id: "South", capacity: 5, queue: [2, 1, 2, 3] },
  { id: "West", capacity: 3, queue: [5, 2, 1, 4] },
];

function initializeThroughput(gates) {
  const summary = {};
  for (const gate of gates) {
    summary[gate.id] = 0;
  };
  return summary;
}

function processGateFlow(gate, tickIndex) {
  let currentTickQueue = gate.queue[tickIndex];
  let processed = 0;
  while (currentTickQueue > 0 && processed < gate.capacity) {
    currentTickQueue--;
    processed++;
  }
  return {
    processed: processed,
    overflow: currentTickQueue
  };
}

function rerouteOverflow(gates, currentGate, tickIndex, overflowAmount) {
  const currentIndex = gates.indexOf(currentGate);
  const nextGateIndex = (currentIndex + 1) % gates.length;
  gates[nextGateIndex].queue[tickIndex] += overflowAmount;
  console.log(
    overflowAmount + " attendees rerouted to " +
    gates[nextGateIndex].id
  );
}

function handleGateAtTick(gates, gate, tickIndex, throughputSummary) {
  console.log("\nProcessing " + gate.id + "...");
  console.log(
    gate.queue[tickIndex] + " attendees arriving."
  );
  const result = processGateFlow(gate, tickIndex);
  throughputSummary[gate.id] += result.processed;
  if (result.overflow > 0) {
    console.log(
      "Overflow of " + result.overflow +
      " attendees. Rerouting..."
    );
    rerouteOverflow(gates, gate, tickIndex, result.overflow);
  }
}

function printSummary(summary) {
  console.log("\nThroughput Summary");
  for (const gateId in summary) {
    console.log(
      gateId + ": " + summary[gateId] +
      " attendees processed"
    );
  }
}

function simulateFestival(gates, timeBlock) {
  console.log("\n" + timeBlock + " Simulation");
  const throughputSummary = initializeThroughput(gates);
  const maxTicks = gates[0].queue.length;
  let tickIndex = 0;
  console.log("\nTick " + (tickIndex + 1));

// User Editable Region

  while (tickIndex < maxTicks) {
    console.log("\nTick " + (tickIndex + 1));
    for(const gate of gates) {
      handleGateAtTick(gates, gate, tickIndex, throughputSummary);
    }
    tickIndex++;

// User Editable Region

  }
}

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Challenge Information:

Build a Festival Crowd Flow Simulator - Step 30

2

there is something wrong with your code. The test doesn’t need you to do add two log statements, just one.

3

Good catch by hbar1st. The issue is that you have the console.log for the tick outside the while loop before it starts, and then again inside the loop. So on the first iteration it logs twice — once from the line before the loop runs and once from inside it. The one before the loop should be removed since the loop already handles all the logging from tick 1 onward.