免費和 Mistral Large 4 線上聊天，打開瀏覽器就能用

function getTopCustomersBySpend(orders) {
  const totalsByCustomer = {};

  for (const order of orders) {
    totalsByCustomer[order.customerId] =
      (totalsByCustomer[order.customerId] || 0) + order.amount;
  }

  return Object.entries(totalsByCustomer)
    .map(([customerId, totalSpend]) => ({ customerId, totalSpend }))
    .sort((a, b) => b.totalSpend - a.totalSpend)
    .slice(0, 3);
}

// Usage: getTopCustomersBySpend([{customerId: "c1", amount: 100}, {customerId: "c2", amount: 200}, {customerId: "c1", amount: 50}])
// → [{customerId: "c2", totalSpend: 200}, {customerId: "c1", totalSpend: 150}]