我有这个代码有几个功能，差不多完成了，我只是在找到我的程序的租金成本。 我的程序读取汽车的文本文件和租赁费用，如下所示：
2014 Toyota Tacoma 115.12 1
2012 Honda CRV 85.10 0
2015 Ford Fusion 90.89 0
2013 GMC Yukon 110.43 0
2009 Dodge Neon 45.25 1
2011 Toyota Rav4 65.02 1
2012 Mazda CX5 86.75 1
2016 Subaru Outback 71.27 0
2015 Ford F150 200.83 1
2010 Toyota Corolla 50.36 1
浮动字符是价格（租赁费用）
但是我希望用户输入车号（1-10）选择多少天并输出租车费用。我只是遇到了如何读取用户想要的汽车输入的问题。这是我的主要代码，但我需要判断案例3是否需要工作。
#include <iostream>
#include <fstream>
using namespace std;
struct car {
int year;
char make[10];
char model[10];
float price;
int available;
} ;
void menu();
// Main Function
int main ()
{
// declare variables
int carAmount = 10;
int choice;
car carLib[carAmount];
char filename[10];
ifstream carInData;
float mostExpensive = 0;
int MostExpensiveIndex;
int count = 0;
int days;
int rentalCost = 0;
bool menu1 = false;
//prompt user for input file
cout << " Enter file name: ";
cin >> filename;
// Start loop menu
while(menu1 = true){
menu();
carInData.open(filename);
cin >> choice;
if (carInData.is_open()) {
// read list of names into array
for (; count < carAmount; count++) {
carInData >> carLib[count].year >> carLib[count].make >> carLib[count].model >> carLib[count].price >> carLib[count].available;
}
}
switch (choice) {
// Case 1 closes menu
case 1:
return 0;
break;
// Case 2 displays if car is available if 1, unavailable if 0
case 2:
// itterate through car array
for(count = 0; count < carAmount; count++){
// Displays if car is available or not
if (carLib[count].available == 1)
cout << " Available ";
else
cout << " Unavailable ";
// Display Cars
cout << carLib[count].year << " " << carLib[count].make << " " << carLib[count].model << " " << carLib[count].price << " " << "\n";
}
break;
// Display only available cars
case 3:
// itterate through car array
for(count = 0; count < carAmount; count++){
// Displays only available cars
if (carLib[count].available == 1){
cout << " Available ";
// Display Cars
cout << carLib[count].year << " " << carLib[count].make << " " << carLib[count].model << " " << carLib[count].price << " " << "\n";
}
}
break;
// Calculates rental cost
case 4:
cout << " Enter car number and how many days " << "\n";
cout << " Days: ";
cin >> days;
cout << "\n" << "Car: ";
cin >> carLib[count].price;
rentalCost += days*count;
cout << " Rental Cost for " << days << " days is " << rentalCost << "\n";
break;
// Finds most expensive car
case 5:
MostExpensiveIndex = count;
for (size_t carIndex = 0; carIndex < carAmount; ++carIndex) {
if (carLib[carIndex].price <= mostExpensive) continue;
mostExpensive = carLib[carIndex].price;
MostExpensiveIndex = carIndex;
}
const car & carI = carLib[MostExpensiveIndex];
cout << " Most Expensive car is: " << " " << carI.year << " " << carI.make << " " << carI.model << " " << carI.price << "\n";
break;
}
}
return 0;
}
void menu()
{
cout << " 1 - Exit program.\n";
cout << " 2 - Show Cars\n";
cout << " 3 - Show only available cars.\n";
cout << " 4 - Rental Cost\n";
cout << " 5 - Most Expensive Car\n";
}
答案 0 :(得分：0)
除非我误解了你的代码是如何工作的，否则我认为案例3工作正常。但是，你应该担心的是案例4
case 4:
cout << " Enter car number and how many days " << "\n";
cout << " Days: ";
cin >> days;
cout << "\n" << "Car: ";
cin >> carLib[count].price; // WHY IS THE USER CHANGING THE PRICE?
rentalCost += days*count; // WHY IS THE PRICE "DAYS * (CAR ID #)"
cout << " Rental Cost for " << days << " days is " << rentalCost << "\n";
break;
你可以在那里看到我的评论。我会把它改成
case 4:
cout << " Enter car number and how many days " << "\n";
cout << " Days: ";
cin >> days;
cout << "\n" << "Car: ";
cin >> count ;
// Note the decrement of 'count' by one, since you expect the user
// to enter a number 1-10
// Should probably include a check that the 'count' is valid
rentalCost += days*carLib[count-1].price;
cout << " Rental Cost for " << days << " days is " << rentalCost << "\n";
break;
请注意，carLib从0-> 9递增，但您的用户可能认为它从1-10开始计算。当您打印选项2（所有汽车信息）时，您可能会有所帮助，其中包含您希望从用户那里获得的汽车ID号。
另外还有一些问题
int（不确定是否按设计），所以请记住days*price计算将四舍五入。