C++ You are a programming intern at a bank and your boss has come to ask for you

Question

C++

You are a programming intern at a bank and your boss has come to ask for your help. When adding all the values in the accounts to compute a total, the result is often totally wrong.

Part 1:

It occurs to you that when dealing with really large values the computation overflows if you use a fixed size data type like int or long. You plan to design a class that can handle arbitrarily large values and support a few simple operations. Since all the values are nonnegative integers (all calculations are done in pennies and there is no “half pennies”) you decide to use a string data member to represent the numeric value.

Hints:

– Number.h header file has been given to you. All you need to do is implement Number.cpp.

– Comment out all functions except Number(), Number(string val), getValue() first and implement those. Once you have tested your simplified class with them, comment back in, one function at a time, pretty much in the order given. Implement the function, test it, move on to the next function, repeat.

– operator<< relies on print function to do all the work (cout<> relies on read function (cin>>n1 does the same thing as n1.read(cin)) to do all the work. Once you have print and read functions all you have to do is use them in operator << and >>.

– You may find the Number With Operators example in Unit 14 Demo Source pretty useful for this.

– For operator + you will need to combine two number strings into a third string which represents the sum of the two, one digit at a time just like in grade school. Once you have that string create a Number with that value and return it. – To get the numeric value of a char you can subtract '0' from it, e.g.: string num = "142"; int four = num[1] - '0';

Part 2:

Your boss is very happy your Number class can handle really large values but she would also like another number class which has all the capabilities of Number but slightly different behaviors useful in modern accounting :) A FunnyNumber does strange math. For example, 2 + 2 = 22, 100 + 1 = 1001. For equality testing, two funny numbers are considered equal if they both use the same digits, regardless of numeric value. For example 100 == 101 (both use 0 and 1), 123321 == 231, 112 != 223 (one uses 1 and 2, the other uses 2 and 3). It also has a new member function which reverses a number. E.g. 1234 becomes 4321, 1200 becomes 21, 0 stays 0.

Hints:

– Make a FunnyNumber.h header which extends Number.h, add two constructors to it and verify that it works just like a Number

– Add a void reverse() function and implement it. – Override operators + and == in FunnyNumber so they have a different behavior.

(The header file)

#ifndef NUMBER_H#define NUMBER_H
#include <iostream>#include <string>
using namespace std;
class Number {public:    // Make a number with value 0    Number();    // Make a number with value val    Number(string val);
    // Get the number's value    virtual string getValue() const;
    // Print this number to the stream    virtual void print(ostream& stream) const;
    // Read this number from the stream    virtual void read(istream& stream);
    // Overload the insertion operator    friend ostream& operator <<(ostream& outs, const Number& n);
    // Overload the extraction operator    friend istream& operator >>(istream& ins, Number& n);
    // Operator +    virtual Number operator+ (const Number& other) const;
    // Operator ==    virtual bool operator== (const Number& other) const;
protected:    string value;};
#endif // NUMBER_H

(Sample main)

#include <iostream>

#include <Number.h>

#include <FunnyNumber.h>
using namespace std;
int main(){

cout<<"Math with regular ints:"<<endl;   

uint num1 = 2800000000;    uint num2 = 3000000000;  

  cout<<num1<<" + "<<num2<<" = "<<num1+num2<<endl;

   cout<<"ouch...!"<<endl;

cout<<endl;
cout<<"We can handle really large values."<<endl;
Number n1, n2;
cout<<"Enter a really big positive integer: ";
// n1.read(cin);
// n1.print(cout); cout<<endl;
cin>>n1;
cout<<"Enter another really big integer: ";
cin>>n2;
cout<<n1<<" + "<<n2<<" = "<<n1+n2<<endl;
n1 = Number("123456789012345678901234567890");
n2 = Number("213456789012345678901234567890");
if (n1 == n2) {
cout<<n1<<" == "<<n2<<endl;
} else {
cout<<n1<<" != "<<n2<<endl;
}
cout<<endl;

cout<<"We can do fancy math too."<<endl;
FunnyNumber f1, f2;
cout<<"Enter a positive integer: ";
cin>>f1;
cout<<"Enter another positive integer: ";
cin>>f2;
cout<<f1<<" + "<<f2<<" = "<<f1+f2<<endl;

f1 = FunnyNumber("123456789012345678901234567890");
f2 = FunnyNumber("999999999912345678901234567890000000000000000");
if (f1 == f2) {
cout<<f1<<" == "<<f2<<endl;
} else {
cout<<f1<<" != "<<f2<<endl;
}

f2.reverse();
cout<<"Reversed value "<<f2<<endl;

return 0;
}

Explanation / Answer

Here is the file of Number.cpp:

#include<iostream>
#include <string>
#include <algorithm> //added to compute reverse of the string
#include "Number.h"

using namespace std;
Number::Number(){
value="0";
}
Number::Number(string val){
value=val;
}
string Number:: getValue() const{
return value;
}
void Number::print(ostream& stream) const{
stream<<value; //print ostream
}
void Number::read(istream& stream){
stream>>value;
}
ostream& operator <<(ostream& outs, const Number& n){
n.print(outs);
return outs;
}
istream& operator >>(istream& ins, Number& n){
n.read(ins);
return ins;
}
Number Number::operator+ (const Number& other) const{
string str1=other.getValue();
string str2=value;   
if (str1.length() > str2.length()) //str2 is the larger one
swap(str1, str2);
string str = "";
int n1 = str1.length(), n2 = str2.length();
int diff = n2 - n1;
int carry = 0; //in case of addition goes above 10
for (int i=n1-1; i>=0; i--)
{
int sum = ((str1[i]-'0') +
(str2[i+diff]-'0') +
carry);
str.push_back(sum%10 + '0');
carry = sum/10;
}
for (int i=n2-n1-1; i>=0; i--)
{
int sum = ((str2[i]-'0')+carry);
str.push_back(sum%10 + '0');
carry = sum/10;
}
if (carry)
str.push_back(carry+'0');
reverse(str.begin(), str.end());
Number addition(str);
return addition;
}
bool Number::operator== (const Number& other) const{
string second=other.getValue(); if(second.length()!=value.length())return false;

for(int i=0;i<second.length() && i<value.length();i++){ //iterating through all the length
if(second[i]!=value[i])return false;
}
return true;
}

And this is your FunnyNumber.h

#ifndef FUNNYNUMBER_H
#define FUNNYNUMBER_H
#include <iostream>
#include <string>
#include <algorithm>
#include "Number.h"
using namespace std;
class FunnyNumber: public Number{
public:
FunnyNumber(){
value="0";
}
FunnyNumber(string val){
value=val;
}

void reverse(){
std::reverse(value.begin(), value.end());
value.erase(0, value.find_first_not_of('0')); //removing leading zeroes
}
virtual FunnyNumber operator+ (const FunnyNumber& other) const{
string check=value;
check+=other.getValue();
FunnyNumber addition(check);
return addition;
  
}

virtual bool operator== (const FunnyNumber& other) const{
string str1=other.getValue();
string str2=value;   
int flag=0;
if (str1.length() > str2.length())
swap(str1, str2);
for(int i=0;i<str1.length();i++){
flag=0;
for(int j=0;j<str2.length();j++){
if(str1[i]==str2[j])flag=1;
}
if(flag!=1) return false;
}
return true;
}

};
#endif

If you have doubt regarding any statement, let me know !

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