以C+显示小数点+；，计算问题 我正在攻读C++在线课程（可能是个错误），我正试图找出如何纠正这个代码。我不得不从头开始写一个程序，我完全被弄糊涂了，我做的不对

这是应该出来的：

Blockquote欢迎使用name的地毯计算器

输入要铺地毯的房间的名称：卧室

输入房间的长度（以英尺为单位）：10

输入房间的宽度（以英尺为单位）：10

输入每码地毯的价格：3.49

输入填充成本：35

                                         Carpet estimate for bedroom

房间总面积：100平方英尺

房间总面积：12平方码

所需地毯的总成本：41.88

劳动力总成本（6.03美元/码）：72.36

填充成本：35.00

小计：149.24

税款：8.50

总数：157.74

大宗报价

一些附加规则是：房间的平方码是用总平方英尺除以9计算的。任何分数差加1码。 安装地毯的人工成本为6.03美元/码 目前税率为5.7%

以下是我当前的代码：

    // John Mayer Learning Unit 2 Assessment

#include <iostream>
using namespace std;


int main()
{
    string roomName; // declarations
    int roomLength;  
    int roomWidth;
    int squareFeet;
    int carpetPrice;
    int paddingCost;
    int totalCarpetCost;
    const int TAX_RATE = .057;
    int laborCost;
    const int LABOR_RATE = 6.03;
    int squareYard;
    int subtotal;
    int taxCost;
    int totalCost;

    cout << "Welcome to John Mayer's Carpet Calculator!"; // displays this at the top
    cout << "\n\n What is the name of the room to be carpeted?"; // asks for the room name
    cin >> roomName; // stores the room name
    cout << "\n What is the length of the room (in feet)?"; // asks for the length
    cin >> roomLength; // stores the length
    cout << "\n What is the width of the room (in feet)?"; // asks for the width
    cin >> roomWidth; // stores the width
    cout << "\n What is the price of the carpet per yard?"; // asks for the price of the carpet
    cin >> carpetPrice; // stores the price
    cout << "\n What is the padding cost?"; // asks for the padding cost 
    cin >> paddingCost; // stores the padding cost **DOES NOT WORK**

    squareFeet = roomLength * roomWidth; // finds square feet by multiplying length and width
    squareYard = (squareFeet / 9) + 1; // finds the square feet and rounds up to the next yard
    totalCarpetCost = carpetPrice * squareYard; // finds the carpet cost by multiplying the input carpet price by the square yardage
    laborCost = squareYard * LABOR_RATE; // finds the labor cost by multiplying the yardage by the labor rate of 6.03
    subtotal = (totalCarpetCost + paddingCost + laborCost); // finds the subtotal by adding the labor cost, carpet cost, and padding cost
    taxCost = subtotal * TAX_RATE; // finds the tax cost by multiplying the subtotal by the tax rate of .057 (5.7%)
    totalCost = taxCost + subtotal; // adds the subtotal and tax to find the total overall cost


    cout << "\n Carpet estimate for " << roomName; // displays text and the room name

    cout << "\n Total square feet of the room: " << squareFeet; //displays the square feet calculation **CORRECT
    cout << "\n Total square yards of the room: " << squareYard; // displays the square yards calculation **CORRECT
    cout << "\n\n Total cost of the carpet needed: " << totalCarpetCost; // displays the carpet cost **INCORRECT
    cout << "\n Total cost of labor (at $6.03/yd): " << laborCost; // displays the labor cost 
    cout << "\n Padding Cost: " << paddingCost; // displays the padding cost 
    cout << "\n\n Subtotal: " << subtotal; // displays the subtotal
    cout << "\n Tax: " << taxCost; // displays the tax calculation
    cout << "\n Total: " << totalCost;  // displays the final total cost
    cout << "\n"; // line break


    system("PAUSE"); 
  return 0;


} 

//约翰·迈耶学习单元2评估
#包括
使用名称空间std；
int main（）
{
字符串roomName；//声明
室内长度；
室内宽度；
整数平方英尺；
国际地毯价格；
内部填充成本；
国际总成本；
成本税税率=0.057；
国际劳工成本；
劳动力成本率=6.03；
整数平方码；
整数小计；
国际税收成本；
总成本；
cout roomName；//存储房间名称
cout>roomLength；//存储长度
cout>roomWidth；//存储宽度
cout>price；//存储价格
cout>paddingCost；//存储填充成本**不起作用**
SquareFoots=roomLength*roomWidth；//通过乘以长度和宽度查找平方英尺
squareYard=（squareFeet/9）+1；//查找平方英尺并向上取整到下一个码
Total地毯成本=地毯价格*平方码；//通过将输入地毯价格乘以平方码来查找地毯成本
laborCost=squareYard*LABOR_RATE；//通过将码数乘以6.03的人工费率来计算人工成本
小计=（总地毯成本+填充成本+人工成本）；//通过添加人工成本、地毯成本和填充成本来查找小计
taxCost=小计*税率；//通过小计乘以.057（5.7%）的税率来查找税收成本
totalCost=taxCost+subtotal；//添加小计和税以查找总成本
cout如果使用小数，则需要使用
double
而不是
int
。
double
是一种浮点类型。
int
（整数）是一个整数，而不是一个小数。因此，将
int
用于小数将不起作用

int a = 1.22;
cout << a << endl;
//this will display 1
double b = 1.22;
cout << b << endl;
//this will display 1.22

inta=1.22；
我想起来了，唯一的问题是税收减少了一便士。我不知道为什么，但已经足够接近了

最终代码：

    // John Mayer Learning Unit 2 Assessment

#include <iostream>
#include <iomanip>
using namespace std;


int main()
{
    string roomName; // declarations
    double roomLength;  
    double roomWidth;
    double squareFeet;
    double carpetPrice;
    double paddingCost;
    double totalCarpetCost;
    const double TAX_RATE = .057;
    double laborCost;
    const double LABOR_RATE = 6.03;
    int squareYard;
    double subtotal;
    double taxCost;
    double totalCost;

    cout << setw(15)<<""<< "Welcome to John Mayer's Carpet Calculator!"; // displays this at the top
    cout << "\n\n What is the name of the room to be carpeted? "; // asks for the room name
    cin >> roomName; // stores the room name
    cout << "\n What is the length of the room (in feet)? "; // asks for the length
    cin >> roomLength; // stores the length
    cout << "\n What is the width of the room (in feet)? "; // asks for the width
    cin >> roomWidth; // stores the width
    cout << "\n What is the price of the carpet per yard? "; // asks for the price of the carpet
    cin >> carpetPrice; // stores the price
    cout << "\n What is the padding cost? "; // asks for the padding cost 
    cin >> paddingCost; // stores the padding cost (this didn't originally work because carpetPrice was int, not double

    squareFeet = roomLength * roomWidth; // finds square feet by multiplying length and width
    //squareYard = (squareFeet / 9) + 1; // (Original code before realizing a 3x3 room would not work correctly
    squareYard = squareFeet / 9; // finds square yardage
    if ((int)squareFeet % 9 != 0)  // if the remainder does not equal 0 after dividing by nine, then...
        {squareYard++;} // ...round up 1
    totalCarpetCost = carpetPrice * squareYard; // finds the carpet cost by multiplying the input carpet price by the square yardage
    laborCost = squareYard * LABOR_RATE; // finds the labor cost by multiplying the yardage by the labor rate of 6.03
    subtotal = (totalCarpetCost + paddingCost + laborCost); // finds the subtotal by adding the labor cost, carpet cost, and padding cost
    taxCost = subtotal * TAX_RATE; // finds the tax cost by multiplying the subtotal by the tax rate of .057 (5.7%)
    totalCost = taxCost + subtotal; // adds the subtotal and tax to find the total overall cost
    cout << "\n\n" << setw(20) << "" << "Carpet estimate for " << roomName; // displays text and the room name

    cout << "\n\n Total square feet of the room: " << squareFeet; //displays the square feet calculation **CORRECT
    cout << "\n\n Total square yards of the room: " << squareYard; // displays the square yards calculation **CORRECT
    cout << "\n\n\n Total cost of the carpet needed: " << totalCarpetCost; // displays the carpet cost **INCORRECT
    cout << "\n\n Total cost of labor (at $6.03/yd): " << laborCost; // displays the labor cost 
    cout << std::fixed << std::setprecision(2) << "\n\n Padding Cost: " << paddingCost; // displays the padding cost 
    cout << std::fixed << std::setprecision(2) << "\n\n\n Subtotal: " << subtotal; // displays the subtotal
    cout << std::fixed << std::setprecision(2) << "\n\n Tax: " << taxCost; // displays the tax calculation
    cout << std::fixed << std::setprecision(2) << "\n\n Total: " << totalCost; // displays the final total cost
    cout << "\n\n"; // line break


    system("PAUSE"); 
  return 0;


}

//约翰·迈耶学习单元2评估
#包括
#包括
使用名称空间std；
int main（）
{
字符串roomName；//声明
双室长；
双室宽；
双平方英尺；
双倍价格；
双重填充成本；
双重总成本；
常数双倍税率=0.057；
双重人工成本；
施工双人工率=6.03；
整数平方码；
双倍小计；
双重征税成本；
总成本加倍；
cout-price；//存储价格
cout>paddingCost；//存储填充成本（这最初不起作用，因为价格是int，而不是double）
SquareFoots=roomLength*roomWidth；//通过乘以长度和宽度查找平方英尺
//squareYard=（平方英尺/9）+1；//（实现3x3房间之前的原始代码无法正常工作）
squareYard=squareFeet/9；//查找平方码
如果（（int）平方英尺%9！=0）//如果余数除以9后不等于0，则。。。
{squareYard++；}/…四舍五入1
Total地毯成本=地毯价格*平方码；//通过将输入地毯价格乘以平方码来查找地毯成本
laborCost=squareYard*LABOR_RATE；//通过将码数乘以6.03的人工费率来计算人工成本
小计=（总地毯成本+填充成本+人工成本）；//通过添加人工成本、地毯成本和填充成本来查找小计
taxCost=小计*税率；//通过小计乘以.057（5.7%）的税率来查找税收成本
totalCost=taxCost+subtotal；//添加小计和税以查找总成本
你能不能回顾一下int是什么以及整型算法是如何工作的？我使用了老师提供的所有东西。没有提到这些，但感谢你的精明回答。这句话现在给了我一个问题：好吧，我在顶部添加了#include，这似乎解决了我的一个问题，现在我只需要知道如何正确地使用e执行小数点限制将其放在前面
真是太棒了！这就解决了问题，并使填充成本输入正常工作。我必须将我的计算四舍五入到小数点后2位，这是下一个问题，以及我的“总人工成本”行仍然显示72而不是72.36使用
#include
无法解决另一个不需要使用setprecision的问题（2）不止一次。因为当你做一次setprecision时，它会自动为它下面的所有其他代码做。你可以看到这是的，对不起，这不是我的最终代码，我删除了它，因为我意识到声明在更改之前是正确的：P再次感谢你的帮助！