math - 如何使用Dart计算此数学？

Question

totalDirection = 1540m

1st KM = $10

2nd KM = $8

Others(normal) KM = $5

如何计算此逻辑？用户应为第一公里支付10美元，然后为2ns公里支付8美元，其他用户则支付5美元。 model.startUpCharge是数组，存储10 $和$ 8

/// [totalDistance] is in meters
double calculateTripPrice(RideModel model, double totalDistance) {
  double totalPrice = 0;
  double standardPrice = 0;

  totalPrice = model.normalCharge *
      ((totalDistance / 1000) - model.startUpCharge.length);
  for (var i = 0; i < model.startUpCharge.length; i++) {
    standardPrice = standardPrice + model.startUpCharge[i];
  }
  totalPrice = totalPrice + standardPrice;
  return totalPrice;
}

1540m逻辑= 1000m支付$ 10和540m支付$ 8

@creativecreatoror可能无法回答

答案应该是50，但结果是5。

问题是:如果我增加1米，价格应该是50。第1公里有初始费用。没变

import 'dart:math' as math;

class RideModel{
  final List startUpCharge;
  final double normalCharge;

  RideModel({this.startUpCharge,this.normalCharge});
}
main() {
 calculateTripPrice(RideModel(startUpCharge: [50,51],normalCharge: 10),1);
}

double calculateTripPrice(RideModel model, double totalDistance) {
  var remainingDistance = totalDistance, price = .0;

  // Kilometers with special charge
  for (var i = 0; i < model.startUpCharge.length; i++) {
    price += model.startUpCharge[i] / 1000 * math.min(1000, remainingDistance);
    remainingDistance -= math.min(1000, remainingDistance);
  }

  // Remaining kilometers
  price += model.normalCharge / 1000 * remainingDistance;
  remainingDistance = 0;
  print(price);

  return price;
}

Answer 1

您可以简单地反复添加价格并从距离中减去。基于此，只有在仍存在剩余距离且每次使用正确的系数时，才会添加价格。

double calculateTripPrice(RideModel model, double totalDistance) {
  var remainingDistance = totalDistance, price = .0;

  // Kilometers with special charge
  for (var i = 0; i < model.startUpCharge.length; i++) {
    price += model.startUpCharge[i] / 1000 * math.min(1000, remainingDistance);
    remainingDistance -= math.min(1000, remainingDistance);
  }

  // Remaining kilometers
  price += 5 / 1000 * remainingDistance;
  remainingDistance = 0;

  return price;
}

记住要 import 'dart:math' as math;。