I'm having trouble refactoring this code into functions. What exactly am I supposed to enter for return to complete these last two functions. They include loops with total and subtotal with multiple calculations based on what character is entered. I understand the first two, just return the variable declared.
#include <iostream>
#include <iomanip>
using namespace std; // forgive me for being lazy!
double getPrice();
int getNumber();
double saleTotal(double getPrice, int getNumber);
void retail(double getPrice, int getNumber, double saleTotal);
const double TAX_RATE = .05;
int main()
{
double myPrice = getPrice();
int myNumber = getNumber();
double getTotal = saleTotal(myPrice, myNumber);
retail;
return 0;
}
double getPrice()
{
double price;
cout << "Enter price $";
cin >> price;
return price;
}
int getNumber()
{
int number;
cout << "Enter number purchased: ";
cin >> number;
return number;
}
double saleTotal(double getPrice, int getNumber)
{
char saleType;
double total;
double subTotal;
cout << "Type W if this is wholesale purchase. \n"
<< "Type R if this is retail purchase. \n"
<< "then press return... \n";
cin.ignore();
cin.get(saleType);
if ((saleType == 'W') || (saleType == 'w'))
{
total = getPrice * getNumber;
return total;
}
else if ((saleType == 'R') || (saleType == 'r'))
{
subTotal = getPrice * getNumber;
total = subTotal + subTotal * TAX_RATE;
return total;
}
else
{
cout << "Error in the input...";
}
}
void retail(double getPrice, int getNumber, double saleTotal)
{
char saleType;
cout << setprecision(2) << fixed << showpoint << getNumber << " items at $" << getPrice << endl;
cout << "Total bill $" << saleTotal;
if ((saleType == 'R') || (saleType == 'r'))
{
cout << " includes sales tax.\n";
}
return;
}
As the name of the methods suggest, you need:
double subTotal()
{
...
return mySubTotal;
}
and:
double total()
{
...
return total;
}
However in the total() method, saleType variable is used uninitialized, as #ThomasSablik commented, which means that your code invokes Undefined Behavior (UB) here:
if ((saleType == 'R') || (saleType == 'r'))
since you are checking an uninitialized variable in the conditions of this if statement.
subTotal() also invokes UB for the same reason. Initialize the variable.
Your functions subTotal(); and total don't know about myPrice and myNumber variables from main().
You declare new variables with the same names, but they are NOT connected to the original ones.
You need to pass those variables from main() into oter functions.
Related
I'm a student in a basic programming class and I'm trying to complete this program for a class assignment. It's a simple program that calculates compounded interest by the inputs of the user. However, when writing the code, I noticed that the the result is 0 even though based on the input I would expect otherwise. Could anyone tell me why the program isn't showing results?
#include <iostream>
#include <cmath>
using namespace std;
// Declarations of Prototype
void futureValue(double* presentValue, float* interestRate, int* months, double* value);
// List of variables
double presentValue = 0;
float interestRate = 0;
double value = 0;
int months = 0;
// Start of Main function
int main(void)
{
cout << "What is the current value of the account?";
cin >> presentValue;
cout << "How many months will Interest be added to the account?";
cin >> months;
cout << "And what will be the Interest Rate of the account?";
cin >> interestRate;
cout << "After " << months << " months, your account balence will be $" << value << ".";
return 0;
}
void futureValue()
{
if (presentValue <= 0)
{
cout << "I'm sorry, you must have a current balence of more than 0.00 dollars to calculate.";
return;
}
else
{
value = presentValue * pow(interestRate + 1, months);
return;
}
}
Yes. You are not calling the futureValue function which would compute the value for you. Due to the value not being computed, it remains 0. Fix:
#include <iostream>
#include <cmath>
using namespace std;
// Declarations of Prototype
void futureValue(double* presentValue, float* interestRate, int* months, double* value);
// List of variables
double presentValue = 0;
float interestRate = 0;
double value = 0;
int months = 0;
// Start of Main function
int main(void)
{
cout << "What is the current value of the account?";
cin >> presentValue;
cout << "How many months will Interest be added to the account?";
cin >> months;
cout << "And what will be the Interest Rate of the account?";
cin >> interestRate;
futureValue(); //Here we compute the value
cout << "After " << months << " months, your account balence will be $" << value << ".";
return 0;
}
void futureValue()
{
if (presentValue <= 0)
{
cout << "I'm sorry, you must have a current balence of more than 0.00 dollars to calculate.";
return;
}
else
{
value = presentValue * pow(interestRate + 1, months);
return;
}
}
Consider the following code:
#include <iostream>
using namespace std;
class inventory
{
public:
~inventory()
{
cout << "This Object is being destroyed" << endl;
}
inventory()
{
itemNumber = 0;
quantity= 0;
cost= 0;
}
inventory(int itemNumber1, int quantity1, double cost1)
{
setItemNumber(itemNumber1);
setQuantity(quantity1);
setCost(cost1);
}
void setItemNumber(int itemNumber2)
{
itemNumber=itemNumber2;
}
bool setQuantity(int quantity2)
{
bool userTrue = true;
bool userFalse = false;
if (quantity2 < 0)
{
quantity = 0;
return userFalse;
}
else
{
quantity= quantity2;
return userTrue;
}
}
bool setCost(double cost2)
{
bool userTrue = true;
bool userFalse = false;
if (cost2 < 0.0)
{
cost = 0.0;
return userFalse;
}
else
{
cost= cost2;
return userTrue;
}
}
double getTotalCost(int quantity, double cost)
{
int total;
total = (quantity * cost);
return total;
}
private:
int itemNumber;
int quantity;
double cost;
};
int main()
{
int itemNumberInput;
int quantityInput;
double costInput;
cout << "Enter the Item Number: " << endl;
cin >> itemNumberInput;
cout << "Enter the Quantity : " << endl;
cin >> quantityInput;
cout << "Enter the Cost : " << endl;
cin >> costInput;
inventory *pointerA, *pointerB;
pointerA = new inventory;
pointerB = new inventory(inventory(itemNumberInput , quantityInput , costInput));
inventory firstObject(itemNumberInput,quantityInput,costInput);
int itemNumberInput1;
int quantityInput1;
double costInput1;
cout << "Enter the Item Number: " << endl;
cin >> itemNumberInput1;
cout << "Enter the Quantity : " << endl;
cin >> quantityInput1;
cout << "Enter the Cost : " << endl;
cin >> costInput1;
inventory secondObject(itemNumberInput1,quantityInput1,costInput1); // not sure if thats correct
cout << secondObject.setItemNumber(); // not working
cout << secondObject.setQuantity(); // not working
cout << secondObject.setCost(); // not working
return 0;
}
The code above is supposed to take three user inputs, and send them to the classes, and the classes will do their job.
I'm currently stuck at the end where its giving me an error.
In the second object where the values are asked from the user, it should send these values to the classes.
Instead, I'm getting the error.
How can I resolve this problem?
Here is the fixed code:-
#include <iostream>
using namespace std;
class inventory
{
public:
~inventory()
{
cout << "This Object is being destroyed" << endl;
}
inventory()
{
itemNumber = 0;
quantity= 0;
cost= 0;
}
inventory(int itemNumber, int quantity, double cost)
{
this->itemNumber = itemNumber;
this->quantity = quantity;
this->cost = cost;
}
void setItemNumber(int itemNumber)
{
this->itemNumber=itemNumber;
}
bool setQuantity(int quantity)
{
bool userTrue = true;
bool userFalse = false;
if (quantity < 0)
{
this->quantity = 0;
return userFalse;
}
else
{
this->quantity= quantity;
return userTrue;
}
}
bool setCost(double cost)
{
bool userTrue = true;
bool userFalse = false;
if (cost < 0.0)
{
this->cost = 0.0;
return userFalse;
}
else
{
this->cost= cost;
return userTrue;
}
}
double getTotalCost(int quantity, double cost)
{
return quantity * cost;
}
private:
int itemNumber;
int quantity;
double cost;
};
int main()
{
int itemNumberInput;
int quantityInput;
double costInput;
cout << "Enter the Item Number: " << endl;
cin >> itemNumberInput;
cout << "Enter the Quantity : " << endl;
cin >> quantityInput;
cout << "Enter the Cost : " << endl;
cin >> costInput;
inventory *pointerA, *pointerB;
pointerA = new inventory;
pointerB = new inventory(inventory(itemNumberInput , quantityInput , costInput));
inventory firstObject(itemNumberInput,quantityInput,costInput);
int itemNumberInput1;
int quantityInput1;
double costInput1;
cout << "Enter the Item Number: " << endl;
cin >> itemNumberInput1;
cout << "Enter the Quantity : " << endl;
cin >> quantityInput1;
cout << "Enter the Cost : " << endl;
cin >> costInput1;
// The below line is correct
// inventory secondObject(itemNumberInput1,quantityInput1,costInput1);
//Alternatively
inventory secondObject;
secondObject.setItemNumber(itemNumberInput1);
secondObject.setQuantity(quantityInput1);
secondObject.setCost(costInput1);
delete pointerA; // delete dynamically allocated memory to avoid memory leak
delete pointerB;
return 0;
}
Well you've constructed 'secondObject' object using the 3-arg constructor, using the user-entered values as parameters. Therefore, the member variables of this object are being set via the constructor and using the 'set' methods aren't really necessary. In your case, the set methods would be useful if you wanted to change the values later on. For example, lets pretend the user enters 10, 10, and 2.5 for the values. You're then using the constructor to construct the object with those values. The only difference is you're placing those values into variables first. But it works the same way. If you wanted to change the value of quantity later on, you could do secondObject.setQuantity(2); And the quantity for that object is now set to 2. The reason why your calls to .set aren't working is because you need to pass in parameters to these methods i.e. the value you want to set it to.
In regard to the destructor method being printed, objects are destroyed when they go out of scope so that the memory is released. Normally, nothing would happen in terms of output- the object would just go out of scope and the compiler would free up the memory and go about its' business. However, you've coded a custom destructor that prints out 'The Object is being destroyed', which it is at the end of the main. It's likely your constructor is working fine, I'm just not sure what you expect to be happening. I'd also suggest you read up on memory leaks in C++, especially in regard to the 'new' keyword.
Hello I've ran into some trouble creating a GroceryItem class and using functions to accept and set input from a user.
Currently when I run the dataEntry function, the compiler moves on to the next function before accepting input from the first function.
I've created a test milk object to test my code but It doesn't allow me to enter data before moving to the next input prompt.
Once I can figure out the class functions, I will also create an array of objects and input values for such.
Any advice for how I can go about fixing this class and functions would be greatly appreciated!
#include <iostream>
using namespace std;
class GroceryItem{
private: int stockNumber;
double price = 0.0;
int quantity;
double totalValue;
double setPrice();
int setStockNum();
int setQuantity();
void setTotalValue();
public:
void dataEntry();
void displayValues();
};
int GroceryItem::setStockNum(){
int stock = 0;
cout << "Enter the stock number for the grocery item: ";
do {
cout << "Stock Number(1000-9999): ";
cin >> stock;
} while (!(stock >= 1000 && stock <= 9999));
stockNumber = stock;
return stockNumber;
}
double GroceryItem::setPrice(){
double x = 0.0;
cout << "Enter the price of the item: ";
while (!(x > 0)) {
cout << "Please enter a positive number for price!";
cin >> x;
}
price = x;
return price;
}
int GroceryItem::setQuantity(){
int x = 0;
cout << "Enter the quantity in stock: ";
while (!(x > 0)){
cout << "Please enter a positive number for quantity!";
cin >> x;
}
quantity = x;
return quantity;
}
void GroceryItem::setTotalValue(){
totalValue = (quantity * price);
}
void GroceryItem::dataEntry(){
setStockNum();
system("pause");
setPrice();
system("pause");
setQuantity();
system("pause");
setTotalValue();
}
void GroceryItem::displayValues(){
cout << "Stock number: " << stockNumber;
cout << "\nItem price: " << price;
cout << "\nQuantity on hand: " << quantity;
cout << "\nTotal value of item: " << totalValue;
}
int main(){
GroceryItem Milk;
Milk.dataEntry();
Milk.displayValues();
system("pause");
return 0;
}
Dude, pay attention to the condition of the while statement, the line
!(stock >= 1000 || stock <= 9999)
returns true for stock = 0 (always true, in this case), so the program won't enter the loop.
Maybe you meant something like:
!(stock >= 1000 && stock <= 9999)
AND(&&) not OR(||)
I don't understand why my code is not calculating the birthrate and the deathrate. I keep on getting 0 for both. I included the static_cast<double> to ensure this wouldn't happen. Any feedback / help?
#include <iostream>
#include <string>
using namespace std;
double calculateBirthRate();
double calculateDeathRate();
class PopInfo
{
private:
string cityName;
long totalCityPopulation;
int numberOfBirths;
int numberOfDeaths;
double birthrate;
double deathrate;
int bir;
int dea;
long citpop;
public:
PopInfo()
{
cityName = "";
totalCityPopulation = numberOfBirths = numberOfDeaths = 0;
}
long getPopulation()
{
return totalCityPopulation;
}
int getBirths()
{
return birthrate;
}
int getDeaths()
{
return deathrate;
}
string getCity()
{
return cityName;
}
void setCityName(string nameOfCity)
{
cityName = nameOfCity;
}
void setTotalCityPopulation(long populationOfCity)
{
totalCityPopulation = populationOfCity;
}
void setNumberOfBirths(int birthNumbers)
{
numberOfBirths = birthNumbers;
}
void setNumberOfDeaths(int deathNumbers)
{
numberOfDeaths = deathNumbers;
}
void calculateBirthRate(PopInfo);
void calculateDeathRate(PopInfo);
};
int main()
{
PopInfo newCity;
string cit;
long citpop;
int bir;
int dea;
cout << "What is the city name?: " << endl;
cin >> cit;
cout << "What is the total city population?: " << endl;
cin >> citpop;
while (citpop < 1)
{
cout << "Please enter a valid total city population: " << endl;
cin >> citpop;
}
cout << "What are the number of births?: " << endl;
cin >> bir;
while (bir < 0)
{
cout << "Please enter a valid number of births: " << endl;
cin >> bir;
}
cout << "What are the number of deaths?: " << endl;
cin >> dea;
while (dea < 0)
{
cout << "Please enter a vaild number of deaths: " << endl;
cin >> dea;
}
newCity.setCityName(cit);
newCity.setTotalCityPopulation(citpop);
newCity.setNumberOfBirths(bir);
newCity.setNumberOfDeaths(dea);
cout << endl;
cout << "The city name is " << newCity.getCity() << endl;
cout << "The total city population is " << newCity.getPopulation() << endl;
cout << "The birth rate is " << newCity.getBirths() << endl;
cout << "The death rate is " << newCity.getDeaths() << endl;
return 0;
}
void PopInfo::calculateBirthRate(PopInfo newCity)
{
double birthrate = static_cast<double>(newCity.bir) / newCity.citpop;
}
void PopInfo::calculateDeathRate(PopInfo newCity)
{
double deathrate = static_cast<double>(newCity.dea) / newCity.citpop;
}
You accidentally made birthrate and deathrate as local variables. Remove the leading keyword double, to make it:
void PopInfo::calculateBirthRate(PopInfo newCity)
{
birthrate = static_cast<double>(newCity.bir) / newCity.citpop;
}
void PopInfo::calculateDeathRate(PopInfo newCity)
{
deathrate = static_cast<double>(newCity.dea) / newCity.citpop;
}
Even so, it's kind of strange that you're passing newCity by value – did you mean to store the rates back in the same object, as in:
void PopInfo::calculateBirthRate(PopInfo& newCity)
{
newCity.birthrate = static_cast<double>(newCity.bir) / newCity.citpop;
}
void PopInfo::calculateDeathRate(PopInfo& newCity)
{
newCity.deathrate = static_cast<double>(newCity.dea) / newCity.citpop;
}
or did you mean to operate on the object in-place, as in:
void PopInfo::calculateBirthRate()
{
birthrate = static_cast<double>(bir) / citpop;
}
void PopInfo::calculateDeathRate()
{
deathrate = static_cast<double>(dea) / citpop;
}
I don't think you ever call the functions that calculate birth rate and death rate! That is on top of the issues already identified, but I'm pretty sure it matters... Put a cout debug statement in there and see if I'm right...
Another problem: since "rate" is a number between zero and 1, and your function getBirths returns an int, you are going to run into a rounding problem...
Also not sure you ever set dea and bir in the context of the class (you declare them at the main level). So many places where you are inviting problems...
The easiest solution would be to rewrite these two functions:
double getBirths()
{
return (double)numberOfBirths/citypop;
}
double getDeaths()
{
return (double)numberOfDeaths/citypop;
}
But read your code, and ask yourself what the scope of your variables is, where they are set (and if you ever set them...), where they are used, where you perform type conversions.... You can learn a lot from that.
EDIT
I couldn't help myself, and decided to copy your program and debug it. After a few simplifications in the structure I came up with the following (note I moved the two functions calculateBirthRate and calculateDeathRate inside the class definition for consistency; and I used the "internally known" variables totalCityPopulation etc, rather than some of the "alternative" ones you were using... it was getting very confusing. Finally, as I mentioned in the original answer - I made sure the birth and death rates were actually calculated. I have marked changed lines with //*** :
#include <iostream>
#include <string>
using namespace std;
double calculateBirthRate();
double calculateDeathRate();
class PopInfo
{
private:
string cityName;
long totalCityPopulation;
int numberOfBirths;
int numberOfDeaths;
double birthrate;
double deathrate;
int bir;
int dea;
long citpop;
public:
PopInfo()
{
cityName = "";
totalCityPopulation = numberOfBirths = numberOfDeaths = 0;
}
long getPopulation()
{
return totalCityPopulation;
}
double getBirths() //*** was int
{
return birthrate;
}
double getDeaths() //*** was int
{
return deathrate;
}
string getCity()
{
return cityName;
}
void setCityName(string nameOfCity)
{
cityName = nameOfCity;
}
void setTotalCityPopulation(long populationOfCity)
{
totalCityPopulation = populationOfCity;
}
void setNumberOfBirths(int birthNumbers)
{
numberOfBirths = birthNumbers;
}
void setNumberOfDeaths(int deathNumbers)
{
numberOfDeaths = deathNumbers;
}
//*** this function moved into the class definition
void calculateBirthRate()
{
birthrate = (double)numberOfBirths/totalCityPopulation; //*** using different variables
}
//*** this function moved into the class definition
void calculateDeathRate()
{
deathrate = (double)numberOfDeaths / totalCityPopulation; //*** using different variables
}
};
int main()
{
PopInfo newCity;
string cit;
long citpop;
int bir;
int dea;
cout << "What is the city name?: " << endl;
cin >> cit;
cout << "What is the total city population?: " << endl;
cin >> citpop;
while (citpop < 1)
{
cout << "Please enter a valid total city population: " << endl;
cin >> citpop;
}
cout << "What are the number of births?: " << endl;
cin >> bir;
while (bir < 0)
{
cout << "Please enter a valid number of births: " << endl;
cin >> bir;
}
cout << "What are the number of deaths?: " << endl;
cin >> dea;
while (dea < 0)
{
cout << "Please enter a vaild number of deaths: " << endl;
cin >> dea;
}
newCity.setCityName(cit);
newCity.setTotalCityPopulation(citpop);
newCity.setNumberOfBirths(bir);
newCity.setNumberOfDeaths(dea);
newCity.calculateBirthRate(); //*** added, or it's never calculated
newCity.calculateDeathRate(); //*** added, or it's never calculated
cout << endl;
cout << "The city name is " << newCity.getCity() << endl;
cout << "The total city population is " << newCity.getPopulation() << endl;
cout << "The birth rate is " << newCity.getBirths() << endl;
cout << "The death rate is " << newCity.getDeaths() << endl;
return 0;
}
When I run this code, I get the following:
What is the city name?:
Amsterdam
What is the total city population?:
1234567
What are the number of births?:
12345
What are the number of deaths?:
54321
The city name is Amsterdam
The total city population is 1234567
The birth rate is 0.00999946
The death rate is 0.044
The diff between your code and mine is:
33c33
< double getBirths()
---
> int getBirths()
38c38
< double getDeaths()
---
> int getDeaths()
68,71c68,69
< void calculateBirthRate()
< {
< birthrate = (double)numberOfBirths/totalCityPopulation;
< }
---
> void calculateBirthRate(PopInfo);
> void calculateDeathRate(PopInfo);
73,76d70
< void calculateDeathRate()
< {
< deathrate = (double)numberOfDeaths / totalCityPopulation;
< }
117,118d110
< newCity.calculateBirthRate();
< newCity.calculateDeathRate();
129a122,125
> void PopInfo::calculateBirthRate(PopInfo newCity)
> {
> double birthrate = static_cast<double>(newCity.bir) / newCity.citpop;
> }
130a127,130
> void PopInfo::calculateDeathRate(PopInfo newCity)
> {
> double deathrate = static_cast<double>(newCity.dea) / newCity.citpop;
> }
double birthrate = static_cast<double>(newCity.bir) / newCity.citpop;
...
double deathrate = static_cast<double>(newCity.dea) / newCity.citpop;
Here you are driving two new variable names birthrate and death rate. You're not writing the values two the class data members. Writing the type before the names overwrites it. To change, simply remove it.
birthrate = static_cast<double>(newCity.bir) / newCity.citpop;
...
deathrate = static_cast<double>(newCity.dea) / newCity.citpop;
Ok i've been programming for about a week now, i started with c++. I'm writing a program that is a kind of an arithmetic trainer, you enter the amount of equations you want, you enter your limit for the random number generator, you specify what kind of equations you want(/*-+), then the program uses a for loop and goes through and generates the equations and their answers in a var and then the users input is checked against this var and if they match another var which is counting the right answers is incremented. After the last equation the program tells the user how many they got right out of how many equations, and by dividing the amount of right answers by the amount of questions then multiplying this value by 100 u should obtain the accuracy percentage for this users arithmetic session. Problem is c++ keeps returning to me a friggin 0 value and i cannot for the life of me work out why in the world c++ is doing this.
entire program:
#include <iostream>
#include <string>
#include <ctime>
#include <cstdlib>
using namespace std;
void menu(void);
class session{
public:
session(){
create_session();
}
void create_session(void){
amount = 0;
range_limit = 0;
rights = 0;
answer = 0;
input = 0;
type = "";
while(amount == 0){
cout << "\nHow many equations do you want?: "; cin >> amount;
if(amount < 1){
cout << "\nAmount is too low!";
amount = 0;
}
}
while(range_limit == 0){
cout << "Enter the number range limit: "; cin >> range_limit;
if(range_limit < 1){
cout << "\nRange limit too low!";
range_limit = 0;
}
}
while(type == ""){
cout << "What equation type do you want?: "; cin >> type;
int strlen = type.size();
if(strlen < 1){
cout << "Invalid type input!";
type = "";
}
}
if(type == "+"){
for(int i=0;i<amount;i++){
int a = random();
int b = random();
answer = a + b;
cout << "\n" << a << " + " << b << " = "; cin >> input;
if(answer == input){
rights++;
}
}
}
cout << "\nYou got " << rights << " answers right out of " << amount << " equations." << endl;
cout << "Accuracy percentage: " << getAccuracy() << "%" << endl;
int post_menu=0;
while(post_menu == 0){
cout << "Enter 1 to create another session or 2 to return to the menu: ";
cin >> post_menu;
if(post_menu == 1){
create_session();
}else if(post_menu == 2){
menu();
}else{
cout << "Invalid input: ";
post_menu = 0;
}
}
}
float getAccuracy(){
float x = (rights/amount)*100;
return x;
}
int random(){
int x = 1+(rand()%range_limit);
return x;
}
void set_amount(int a){
amount = a;
}
void set_range_limit(int r){
range_limit = r;
}
void set_rights(int R){
rights = R;
}
void set_answer(int a){
answer = a;
}
void set_input(int i){
input = i;
}
void set_type(string t){
type = t;
}
private:
int amount;
int accuracy;
int range_limit;
int rights;
int answer;
int input;
string type;
};
int main(){
cout << "=== WELCOME TO ARITH! === \n=========================\n";
menu();
return 0;
}
void menu(void){
//Set the seed for random number gen.
srand(time(0));
//Set var for getting menu input, then get the menu input..
int menu_input;
cout << "\n[1]Create a Session. [2]Exit Arith. \nWhat would you like to do?: ";
cin >> menu_input;
//Now we check what the user wants and act accordingly..
if(menu_input > 2){
cout << "error";
menu_input=0;
}else if(menu_input == 1){
session start;
}else if(menu_input == 2){
cout << "\nExiting Arith!";
}else{
cout << "error";
menu_input=0;
}
}
Troublesome part:
float getAccuracy(){
float x = (rights/amount)*100;
return x;
some how the program is returning 0%.
anyone know why this is so and how to get the result im after.
rights and amount both are int , so when you divide the value is floored, for example if you do 5/2 the answer would be 2 instead of 2.5. To solve this you need to cast one of the variable to float like this: (float(rights)/amount) * 100.
when two int numbers are divided the result will also be int even if temporary variable. so you can make any of the variable float or double or cast it.
You need to convert only one data type because the other will be type promoted implicitly.
float x = ((double)rights/amount)*100;
or you can make your amount variable float by default if it doesnt affect any other part of your code.
Also you have the option to static cast:
float x = (static_cast<double>(rights)/amount)*100;