我希望计算客户购买我的产品许可证时的收费金额。
我按许可证范围出售：
因此，当有人购买136个许可证时，我将向他收取：
50 x 2 x $20 = $2000
30 x 1 x $30 = $900
6 x $50 = $300
int getPrice(int n)
{
if (n >= 1 && n <= 10) return 50 * n;
if (n >= 11 && n <= 20) return 40 * n;
if (n >= 21 && n <= 30) return 30 * n;
if (n >= 31 && n <= 50) return 20 * n;
throw new Exception("Impossible");
}
int minimizePrice(int n)
{
int[] minimumPrice = new int[n + 1];
for (int i = 1; i <= n; ++i)
{
minimumPrice[i] = int.MaxValue;
for (int j = Math.Max(0, i - 50); j < i; ++j)
{
minimumPrice[i] = Math.Min(minimumPrice[i],
minimumPrice[j] + getPrice(i - j));
}
}
return minimumPrice[n];
}
这看起来非常类似于为购买做出找零算法（选择哪些硬币）。唯一的区别是你要与一个范围进行比较，而不是单个数字。
代码可能看起来像这样：
var val = 136;
var price = 0;
while (val > 0)
{
var range = FindMatchingRange(val); // Use a dictionary, list, or array.
var number = Math.Min(val, range.Max);
price += range.CostPerUser * number;
val -= number;
}
我为您制作了一个计算类...更加以客户为导向的。 它可以根据您定义的价格范围，计算出最便宜的价格。
50个许可证，每个20美元（因为：31-50：$20/用户）
50个许可证，每个20美元（因为：31-50：$20/用户）
36个许可证，每个20美元（因为：31-50：$20/用户）
50个许可证，每个20美元
50个许可证，每个20美元
30个许可证，每个30美元
类的代码：
public class PriceCalculator
{
public List<OrderPackage> CalculateCheapestPrice(Int32 AmountOfLicenses,
List<PriceRange> PriceRanges, out Double Total)
{
List<OrderPackage> result = new List<OrderPackage>();
Total = 0;
Int32 AmountsOfLicensesleft = AmountOfLicenses;
PriceRanges.Sort(ComparePrice);
for (int i = 0; i < PriceRanges.Count; i++)
{
for (int j = PriceRanges[i].MaxAmount; j >= PriceRanges[i].MinAmount; j--)
{
if (j <= AmountsOfLicensesleft)
{
OrderPackage Order = new OrderPackage();
Int32 AmountOfThisPackage = AmountsOfLicensesleft / j;
//Int32 AmountForThisPrice = Convert.ToInt32(Math.Floor(tmp));
Order.PriceRange = PriceRanges[i];
Order.AmountOfLicenses = j;
Total += Order.AmountOfLicenses * Order.PriceRange.PricePerLicense;
for (int k = 0; k < AmountOfThisPackage; k++)
{
result.Add(Order);
}
AmountsOfLicensesleft = AmountsOfLicensesleft - (AmountOfThisPackage * j);
}
}
}
return result;
}
private static int ComparePrice(PriceRange x, PriceRange y)
{
if (x.PricePerLicense == y.PricePerLicense)
return 0;
if (x.PricePerLicense > y.PricePerLicense)
return 1;
if (x.PricePerLicense < y.PricePerLicense)
return -1;
return 0;
}
public class OrderPackage
{
public PriceRange PriceRange { get; set; }
public Int32 AmountOfLicenses { get; set; }
}
public class PriceRange
{
public int MinAmount { get; set; }
public int MaxAmount { get; set; }
public Double PricePerLicense { get; set; }
}
}
使用示例：
private void button1_Click(object sender, EventArgs e)
{
// Preparing PriceRangeDefinitions
List<PriceCalculator.PriceRange> PriceRangeDefinitions = new List<PriceCalculator.PriceRange>();
PriceRangeDefinitions.Add(new PriceCalculator.PriceRange() { MinAmount = 1, MaxAmount = 10, PricePerLicense = 50 });
PriceRangeDefinitions.Add(new PriceCalculator.PriceRange() { MinAmount = 11, MaxAmount = 20, PricePerLicense = 40 });
PriceRangeDefinitions.Add(new PriceCalculator.PriceRange() { MinAmount = 21, MaxAmount = 30, PricePerLicense = 30 });
PriceRangeDefinitions.Add(new PriceCalculator.PriceRange() { MinAmount = 31, MaxAmount = 50, PricePerLicense = 20 });
// Start the Calculation
PriceCalculator calculator = new PriceCalculator();
Double Total;
List<PriceCalculator.OrderPackage> Packages =
calculator.CalculateCheapestPrice(130, PriceRangeDefinitions, out Total);
// Show Proof of Concept
String ProofOfConcept = String.Empty;
for (int i = 0; i < Packages.Count; i++)
{
ProofOfConcept += Packages[i].AmountOfLicenses.ToString() + " Licenses " +
Packages[i].PriceRange.PricePerLicense.ToString() + "$ each" + Environment.NewLine;
}
ProofOfConcept += Environment.NewLine + "TOTAL: " + Total.ToString();
MessageBox.Show(ProofOfConcept);
}
first 10 licenses (1-10): $50/user
next 10 licenses (11-20): $40/user
next 10 licenses (21-30): $30/user
all licenses after that (31+) : $20/user