我试着用c语言编写一个电价计算程序，但有一行不行'；行不通

我试着用c语言编写一个电价计算程序，但有一行不行

这是我的密码

#include <stdio.h>

int main()
{
    int usageElectric;      //amount of electricity used
    int basicMoney;         //basic price
    int totalMoney;         //total price
    double usageMoneyPerKw; //kw per used price
    double totalFinalMoney; //final usage price
    double tax;             //tax


    printf("put in the amount of electricity used (kw) : ");  //put in 150kw.
    scanf("%d", &usageElectric);

    basicMoney = 660;   //basic price = $660
    usageMoneyPerKw = 88.5; //kw per usage price : $88.5
    totalMoney = basicMoney + (usageElectric * usageMoneyPerKw);    

    tax = totalMoney * (9 / 100);   //This line is the problem line = doesn't work

    totalFinalMoney = totalMoney + tax; 

    printf("Tax is %d\n", tax);  // a line to show that the tax isn't being caluculated properly

    printf("The final usage price is %lf.", totalFinalMoney);

    return 0;
}

如果工作正常，应得出如下结果：

tax = 13935 * (9/100) = 1254.15

因此，最终结果应该是：

The final usage price is 15189.150000

---

在子表达式

9/100

中，两个操作数都是整数，因此除法是整数除法，这意味着任何小数部分都被截断，因此其计算结果为0

如果更改为浮点常量，则会得到浮点除法。因此，将上述内容更改为：

9.0/100.0

或者简单地说：

0.09

---

您只需像这样键入

（9/10）

（（双）9/100）。从现在起，它将9/10的输出视为整数，并将结果视为0

在打印

tax

时，您应该使用

%lf

istead of

%d

#include <bits/stdc++.h>

using namespace std;

int main()
{

    int usageElectric;      //amount of electricity used
    int basicMoney;         //basic price
    int totalMoney;         //total price
    double usageMoneyPerKw; //kw per used price
    double totalFinalMoney; //final usage price
    double tax;             //tax


    printf("put in the amount of electricity used (kw) : ");  //put in 150kw.
    scanf("%d", &usageElectric);

    basicMoney = 660;   //basic price = $660
    usageMoneyPerKw = 88.5; //kw per usage price : $88.5
    totalMoney = basicMoney + (usageElectric * usageMoneyPerKw);    

    tax = totalMoney * ((double)9 / 100);   //This line is the problem line = doesn't work

    totalFinalMoney = totalMoney + tax; 

    printf("Tax is %lf\n", tax);  // a line to show that the tax isn't being caluculated properly

    printf("The final usage price is %lf.", totalFinalMoney);
}

#包括
使用名称空间std；
int main（）
{
int usageElectric；//使用的电量
int basicMoney；//基本价格
int totalMoney；//总价
双重使用MoneyPerkw；//kw/每使用价格
双倍总最终金额；//最终使用价格
双重税；//税
printf（“输入用电量（kw）：”；//输入150kw。
scanf（“%d”和usageElectric）；
基本货币=660；//基本价格=660美元
usageMoneyPerKw=88.5；//kw/每使用价格：$88.5
totalMoney=基本货币+（USAGEEElectric*usageMoneyPerKw）；
tax=totalMoney*（（double）9/100）；//这行是问题行=不起作用
totalFinalMoney=总货币+税收；
printf（“Tax是%lf\n”，Tax）；//一行显示未正确计算税款
printf（“最终使用价格为%lf.”，总最终金额）；
}
9/100
采用整数数学计算；强制其中至少一个为浮点，例如
（9.0/100.0）
，这样整个计算都是在浮点中完成的。它应该是
tax=（totalMoney*9）/100.0您真的不应该使用浮点数来表示货币金额。您应该改为使用整数。这是否回答了您的问题？好的，我明白你的意思了，这是无意的打字错误。
#include <bits/stdc++.h>

using namespace std;

int main()
{

    int usageElectric;      //amount of electricity used
    int basicMoney;         //basic price
    int totalMoney;         //total price
    double usageMoneyPerKw; //kw per used price
    double totalFinalMoney; //final usage price
    double tax;             //tax


    printf("put in the amount of electricity used (kw) : ");  //put in 150kw.
    scanf("%d", &usageElectric);

    basicMoney = 660;   //basic price = $660
    usageMoneyPerKw = 88.5; //kw per usage price : $88.5
    totalMoney = basicMoney + (usageElectric * usageMoneyPerKw);    

    tax = totalMoney * ((double)9 / 100);   //This line is the problem line = doesn't work

    totalFinalMoney = totalMoney + tax; 

    printf("Tax is %lf\n", tax);  // a line to show that the tax isn't being caluculated properly

    printf("The final usage price is %lf.", totalFinalMoney);
}