16:T4fe,function turnstileTimes(arrTime, direction) { const n = arrTime.length; const indexed = arrTime.map((t, i) => [t, i]); indexed.sort((a, b) => a[0] - b[0] || a[1] - b[1]); const result = new Array(n); const enterQueue = []; const exitQueue = []; let enterHead = 0; let exitHead = 0; let time = 0; let i = 0; let lastUsed = -1; while (i < n || enterHead < enterQueue.length || exitHead < exitQueue.length) { while (i < n && indexed[i][0] <= time) { const idx = indexed[i][1]; if (direction[idx] === 1) { enterQueue.push(idx); } else { exitQueue.push(idx); } i += 1; } const enterEmpty = enterHead >= enterQueue.length; const exitEmpty = exitHead >= exitQueue.length; if (enterEmpty && exitEmpty) { time = indexed[i][0]; lastUsed = -1; continue; } let pickExit; if (!exitEmpty && !enterEmpty) { pickExit = lastUsed !== 1; } else { pickExit = !exitEmpty; } if (pickExit) { const idx = exitQueue[exitHead]; exitHead++; result[idx] = time; lastUsed = 0; } else { const idx = enterQueue[enterHead]; enterHead++; result[idx] = time; lastUsed = 1; } time += 1; } return result; }17:T4fe,function turnstileTimes(arrTime, direction) { const n = arrTime.length; const indexed = arrTime.map((t, i) => [t, i]); indexed.sort((a, b) => a[0] - b[0] || a[1] - b[1]); const result = new Array(n); const enterQueue = []; const exitQueue = []; let enterHead = 0; let exitHead = 0; let time = 0; let i = 0; let lastUsed = -1; while (i < n || enterHead < enterQueue.length || exitHead < exitQueue.length) { while (i < n && indexed[i][0] <= time) { const idx = indexed[i][1]; if (direction[idx] === 1) { enterQueue.push(idx); } else { exitQueue.push(idx); } i += 1; } const enterEmpty = enterHead >= enterQueue.length; const exitEmpty = exitHead >= exitQueue.length; if (enterEmpty && exitEmpty) { time = indexed[i][0]; lastUsed = -1; continue; } let pickExit; if (!exitEmpty && !enterEmpty) { pickExit = lastUsed !== 1; } else { pickExit = !exitEmpty; } if (pickExit) { const idx = exitQueue[exitHead]; exitHead++; result[idx] = time; lastUsed = 0; } else { const idx = enterQueue[enterHead]; enterHead++; result[idx] = time; lastUsed = 1; } time += 1; } return result; }18:T4b6,function simulateCallCenter(instructions) { const employees = []; const queue = []; const phoneToEmployee = new Map(); const output = []; for (const op of instructions) { if (op[0] === 'hire') { employees.push({ name: op[1], available: true }); } else if (op[0] === 'dispatch') { const phone = op[1]; if (phoneToEmployee.has(phone) || queue.includes(phone)) continue; const free = employees.find((e) => e.available); if (free) { free.available = false; phoneToEmployee.set(phone, free); output.push(`Connecting ${phone} to ${free.name}`); } else { queue.push(phone); } } else if (op[0] === 'end') { const phone = op[1]; if (!phoneToEmployee.has(phone)) continue; const employee = phoneToEmployee.get(phone); phoneToEmployee.delete(phone); output.push(`Call between ${phone} and ${employee.name} ended`); if (queue.length > 0) { const nextPhone = queue.shift(); phoneToEmployee.set(nextPhone, employee); output.push(`Connecting ${nextPhone} to ${employee.name}`); } else { employee.available = true; } } } return output; }

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