Different Outputs of an Atoi Converted String-> int - c++

Question

Here is my input file:
Plain Egg
1.45
Bacon and Egg
2.45
Muffin
0.99
French Toast
1.99
Fruit Basket
2.49
Cereal
0.69
Coffee
0.50
Tea
0.75
This is my code. I'm having no problem when people order 8 or 9 items, but as soon as they enter 10 or more items, I get really weird results and not the nicely printed check that I would like to see. For instance, let's say someone orders 8 items and they input "12345678" for their order. I get this:
But if the user inputs that they want let's say 15 items and they order "123456781234567", I get THIS:
Even when they order 10 items, I get just a blank check :/ :
What in the world is happening with my program? Does it have to do with me using c-strings? I want to understand what is going on inside my little computer and understand the way my computer thinks. If you can explain me this in a very simple way (I'm really new so I need something very explanatory with definitions of your fancy words) and some way I can understand, because like I said, I'm really new to computer science. Thank you.
// Local Restaurant: The 5,000 Fed
#include <cmath>
#include <cstdlib>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <string>
using namespace std;
struct menuItemType {
string menuItem;
double menuPrice;
};
void getData(menuItemType list[]);
string showMenu(menuItemType list[]);
void printCheck(string y, menuItemType list[]);
int main() {
string y;
menuItemType menuList[8];
cout << "Hello and welcome to the 5,000 fed. Your local Long Beach café, "
"whose name is inspired by Jesus' miraculous manifestation "
"of bread to feed the 5k! His disciples helped him in passing out "
"the bread, and so I am here, your waiter, to help you and assist "
"you with your order. ";
getData(menuList);
y = showMenu(menuList);
printCheck(y, menuList);
return 0;
}
void getData(menuItemType list[]) {
string menupricet[8];
ifstream inFile;
inFile.open("menudata.txt");
for (int i = 0; i < 8; i++) {
getline(inFile, list[i].menuItem);
getline(inFile, menupricet[i]);
}
for (int i = 0; i < 8; i++) {
list[i].menuPrice = atof(menupricet[i].c_str());
}
}
string showMenu(menuItemType list[]) {
int amount;
char number;
string reps;
string response = "y";
string total = "";
cout << fixed << setprecision(2);
cout << endl << endl;
cout << "Here is our wonderful menu. I do recommend the french toast, "
"similar to the bread that Jesus ate."
<< endl
<< endl;
for (int i = 0; i < 8; i++) {
cout << i + 1 << ". " << setw(13) << left << list[i].menuItem << setw(8)
<< right << list[i].menuPrice << endl;
}
cout << endl;
cout << "How to order: Write the number you would like and specify how many "
"you want of that item by typing it in multiple times. For instance "
"an input of \"1135777\" means that you want two plain eggs, one "
"muffin, one fruit basket, and three coffees."
<< endl
<< endl;
cout << "How many items are you ordering total?: ";
cin >> amount;
cout << endl;
cout << "Please input your order, and press enter after your order: ";
for (int i = 0; i < amount; i++) {
cin >> number;
total += number;
}
return total;
}
void printCheck(string y, menuItemType list[]) {
int k = 0;
int temp = 0;
double bill = 0;
int newone = 0;
k = atoi(y.c_str());
while (k != 0) {
newone = newone * 10;
newone = newone + k % 10;
k = k / 10;
}
cout << "Thank you for dining at the 5,000 fed. Here's your check:" << endl
<< endl
<< endl;
cout << "_________________" << endl;
while (newone > 0) {
temp = newone % 10;
newone /= 10;
bill += list[temp - 1].menuPrice;
cout << left << setw(15) << list[temp - 1].menuItem << right << setw(5)
<< "|" << list[temp - 1].menuPrice << endl;
}
cout << fixed << setprecision(2);
cout << left << setw(15) << "Amount Due:" << right << setw(10) << "|" << bill
<< endl
<< endl;
}
EDIT:
So someone asked me to paste the output as text instead of images so here are the three outputs:
They order 8 items such as "12345678":
_________________
Plain Egg |1.45
Bacon and Egg |2.45
Muffin |0.99
French Toast |1.99
Fruit Basket |2.49
Cereal |0.69
Coffee |0.50
Tea |0.75
Amount Due: |11.31
They order 15 items such as "123456781234567":
_________________
French Toast |1.99
\365\277\357\376^ޝ-
YW\300\365\277\357\376all\377
\200\367\277\357\376
\370\277\357\376
\227\370\277\357\376
\331\370\277\357\376%\371\277\357\376\262
|0.00
Coffee |0.50
Muffin |0.99
\362\277\357\376x\362\277\357\376x\362\277\357\376x\362\277\357\376Plain Egg33333 |0.00
Plain Egg |1.45
Cereal |0.69
\365\277\357\376^ޝ-YW\300\365\277\357\376all\377\200\367\277\357\376\370\277\357\376\227\370\277\357\376\331\370\277\357\376%\371\277\357\376\262 |0.00
Cereal |0.69
Amount Due: |6.31
They order 10 items such as "1234567812":
_________________
Amount Due: |0.00

Answer 1

The problem in your code is associated with the size of the type int. Here is the solution, you may declare k and new one as unsigned long int so that they can hold up to 4,294,967,295 which still contains only 10 orders.
As a solution, you can use the string y as it is instead of converting to int. So that you can place as many orders as you wish. To traverse through the orders, you can use substr and length function of the string.
Let me re-write the printCheck function for, if I may
void printCheck(string y, menuItemType list[]) {
double bill = 0;
for(int i = 0; i< y.length(); i++)
{
string a = y.substr(i, 1);
int kk = atoi(a.c_str());
bill += list[kk - 1].menuPrice;
cout << left << setw(15) << list[kk - 1].menuItem << right << setw(5)
<< "|" << list[kk - 1].menuPrice << endl;
}
cout << fixed << setprecision(2);
cout << left << setw(15) << "Amount Due:" << right << setw(10) << "|" << bill << endl;
}
I hop this helps. Regards.