I'm writing a function that handles an order input file (csv) using a while loops to iterate though it.
762212,1,2020-03-15,10951-3,64612-2,57544-1,80145-1,27515-2,16736-1,79758-2,29286-2,51822-3,39096-1,32641-3,63725-3,64007-2,23022-1,16974-3,26860-2,75536-2,26461-1
1,373975319551257,12-2023
258572,2,2020-03-15,96497-1,70616-1,80237-2,22248-2,56107-1,59695-1,37948-3,21316-3,63498-1,18329-1,56833-1,66295-1,47680-3,30346-1
1,201741963232463,02-2022
857003,3,2020-03-15,16655-1,88019-3,75069-3,96017-2,46883-2,15138-1,77316-1,70063-3,54452-3,86429-2,15134-2,60176-1,12946-3
2,cfeeham3s
747893,4,2020-03-17,48520-1,93268-2,63636-1,23750-2,99771-3,83203-1,21316-3,89921-2,15134-3,82831-1,30346-2,54044-3,28561-1,14792-2,23523-3,56826-2
1,3571379825697064,04-2025
Every two lines represents an input. I have the following function that handles this input:
list<Order> orders;
void read_orders(string file_name) {
fstream read_file;
read_file.open(file_name, ios::in);
if (read_file.is_open()) {
string s;
int line_num = 1; // keeps track of line number in input file
int o_id;
string o_date;
int c_id;
vector<LineItem> itms;
while (getline(read_file, s)) {
cout << orders.size(); // shows that only two objects are added before failure
if (line_num % 2 == 1) { // handle odd numbered lines of input
auto data = split(s, ',');
int o_id = stoi(data[0]);
string o_date = data[1];
int c_id = stoi(data[2]);
vector<LineItem> itms;
// get line items
int n_line_items = data.size() - 3;
vector<string> end_data(data.end() - n_line_items, data.end());
for (string x: end_data) {
auto parts = split(x, '-');
LineItem* it = new LineItem(stoi(parts[0]), stoi(parts[1]));
itms.push_back(*it);
delete it;
}
} else { // handle even numbered lines of input
auto data = split(s, ',');
Credit* pay_credit = new Credit(0.0, data[1], data[2]); // initialize each type of payment
PayPal* pay_paypal = new PayPal(0.0, data[1]);
WireTransfer* pay_wire = new WireTransfer(0.0, data[1], data[2]);
if (data[0] == "1") {
Order* ordr = new Order(o_id, o_date, c_id, itms, *pay_credit);
orders.push_back(*ordr);
delete ordr;
} else if (data[0] == "2") {
Order* orr = new Order(o_id, o_date, c_id, itms, *pay_paypal);
orders.push_back(*orr);
delete orr;
} else if (data[0] == "3") {
Order* odr = new Order(o_id, o_date, c_id, itms, *pay_wire);
orders.push_back(*odr);
delete odr;
}
delete pay_credit; // trying to clean up memory
delete pay_paypal;
delete pay_wire;
}
line_num += 1;
}
read_file.close();
}
}
Because of my cout statement, I can tell that it only adds two items to the list before running into the std::bad_alloc error. It seems to happen when it switches from adding a Credit object to adding a PayPal object into the Order(...) when it's initialized. I did a lot of research into why this might happen, so I tried to clean up as much as I knew how to (I'm new to C++) but the same error kept popping up. Does the error happen when I'm adding things to the list or is it when I'm creating these new objects?/How could I fix something like that?
Here are my class definitions in case that's important:
class Payment {
public:
double amount;
string print_detail() {
return "hey";
};
};
class Credit: public Payment {
private:
string card_number;
string expiration;
public:
Credit(double amt, string cn, string exp) {
this->amount = amt;
this->card_number = cn;
this->expiration = exp;
}
string print_detail() {
return "Credit card " + this->card_number + ", exp. " + this->expiration;
}
};
class PayPal: public Payment {
private:
string paypal_id;
public:
PayPal(double amt, string pp_id) {
this->amount = amt;
this->paypal_id = pp_id;
}
virtual string print_detail() {
return "Paypal ID: " + this->paypal_id;
}
};
class WireTransfer: public Payment {
private:
string bank_id;
string account_id;
public:
WireTransfer(double amt, string b_id, string a_id) {
this->amount = amt;
this->bank_id = b_id;
this->account_id = a_id;
}
string print_detail() {
return "Wire transfer from Bank ID " + this->bank_id + ", Account# " + this->account_id;
}
};
class LineItem {
private:
int item_id;
int qty;
public:
LineItem(int i_id, int qt) {
this->item_id = i_id;
this->qty = qt;
}
double subtotal() {
double subtot = 0.0;
for (auto x: items) {
if (x.item_id == this->item_id) {
subtot += x.price * this->qty;
}
}
return subtot;
};
};
class Order {
private:
int order_id;
string order_date;
int cust_id;
vector<LineItem> line_items;
Payment payment;
public:
Order(int o_id, string o_date, int c_id, vector<LineItem> li, Payment pay) {
this->order_id = o_id;
this->order_date = o_date;
this->cust_id = c_id;
this->line_items = li;
this->payment = pay;
}
string pay_type = "";
double total() {
double result = 0.0;
for (auto li: line_items) {
result += li.subtotal();
}
return result;
}
string print_order() {
string text = "===========================\nOrder #";
text += to_string(this->order_id) + ", Date: " + this->order_date + "\nAmount: $";
text += to_string(this->total()) + ", Paid by ";
text += payment.print_detail();
return text;
}
};
And this was the error message showing that it did insert two items:
001122terminate called after throwing an instance of 'std::bad_alloc'
what(): std::bad_alloc
Process returned 3 (0x3)
std::bad_alloc is often thrown when there is not enough memory to be allocated. I can't say if this will solve the problem, but your repeated allocations and deallocations of objects are both unnecessary and harmful (causing memory fragmentation).
Instead of
LineItem* it = new LineItem(stoi(parts[0]), stoi(parts[1]));
itms.push_back(*it);
delete it;
you should do
itms.push_back(LineItem(stoi(parts[0]), stoi(parts[1]));
or
itms.emplace_back(stoi(parts[0]), stoi(parts[1]));
The same applies to every occurence of new in read_orders. You don't need any of them.
Another helpful thing you can do is to preallocate memory for std::vector. If you don't know how many items it will have, do an educated guess (100, 1000, 10000, etc.).
itms.reserve(1000); //before you start to push_back() to it
Also, make sure to std::move your vectors if you want to transfer the whole content of it and not make a copy.
This a menu based program to create a database of people and for performing operations on their name. After compilation, I am able to add a person successfully using the add function of Person class but when I retrieve the list of the added people using list function it shows garbage values instead of showing the entered names. It's the question no. 4(lab 4) in the below give doc.
https://drive.google.com/open?id=18cR9bgPlqM6q-kXBIcxg5Hpj04bkZMnW&authuser=0
#include<iostream>
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
using namespace std;
class Person
{
const char *name;
public:
Person(const char* n)
{
name=n;
}
bool search(const char* substr)
{
const char *str=name;
while(*str!='\0')
{ int count=0;
if(*str==*substr)
{ const char *s=substr;
const char *p=str;
while(*s!='\0')
{
if(*p==*s)
{
count++;
p++;
s++;
}
else
break;
}
}
if(count==strlen(substr))
{
cout<<name<<endl;
return true;
}
str++;
}
return false;
}
void print()
{
cout<<name<<endl;
}
~Person()
{
cout << ":)";
}
friend class People;
};
class People
{
Person** array;
int length;
void prompt()
{
cout << "\n'A'-Add a person\n'L'-List all persons\n'S'-Search\n'Q'-Quit\n";
}
public:
People()
{
array = NULL;
length = 0;
}
void add()
{
string m;
cout << "Enter a Name:\n";
cin >> m;
Person s(m.c_str());
if (array == NULL)
array = (Person**)malloc(sizeof(Person*));
else
{
array=(Person**)realloc(array, length*sizeof(Person*));
}
array[length] =new Person(s.name);
array[length]->print();
++length;
}
void list()
{
cout << "\nThe names of the person in the list are:\n";
for (int i = 0; i <length; i++)
{
array[i]->print();
}
}
void search()
{
string a;
int flag = 0;
cout << "\nEnter a string to be found in the names present in the list:\n";
cin >> a;
cout << "\n The names with entered substring are:\n";
for (int i = 0; i <length; i++)
{
bool state=array[i]->search(a.c_str());
if (state)
flag = -1;
}
if (flag == 0)
cout << "\nNone of the names contains the entered substring!!!\n";
}
void menu()
{
char c = 'Y';
while (c != 'Q')
{
cout << "Choose an option(character):\n";
prompt();
cin>>c;
switch (c)
{
case 'A':add();
cout << "Name entered sucessfully!!!\n";
break;
case 'L':list();
break;
case 'S':search();
break;
case 'Q':c = 'Q';
break;
}
}
}
};
int main()
{
People All;
All.menu();
return 0;
}
I am not able to find any mistake in my implementation of add function. What could be the possible reason for malfunctioning of list function?
tl;dr
You store a pointer to the internal memory of string (m). That string gets destroyed at the end of add() so you have pointer to unallocated memory, which causes undefined behaviour.
possible solutions
Best would be to store a std::string instead of a const char * inside Person.
walkthrough
If you want a more detailed analyses: You store a pointer to a string that goes out of scope.
void add()
{
string m; // string is initialized and allocates memory for its content
cout << "Enter a Name:\n";
cin >> m; // read content
Person s(m.c_str()); // m.c_str() retrieves a pointer to the memory allocated by m
//this pointer is stored inside s
if (array == NULL)
{
array = (Person**)malloc(sizeof(Person*));
}
else
{
array=(Person**)realloc(array, length*sizeof(Person*));
}
array[length] = new Person(s.name); // s.name still points to the memory allocated by m
array[length]->print();
++length;
} //At the end of the function m gets destroyed and deallocates its memory
So after the function exits you still have stored the pointer to m.c_str() inside a persons name. This pointer now points to unallocated memory. This memory now may (or may not) be overwritten at any time. You get undefined behaviour and print garbage.
I'm a student of system engineering, 2nd semester of the ULA (Universidad de los Andes)
So, I'm programming a c++ mini project for university. The project consists of making a draft of a software oriented to buying and selling crypto currencies, however, since yesterday I've been getting a problem with it (a segmentation fault core dumped specifically)... So, as this page had been helpful with my previous programs and this time I didn't find something that could have helped me, I decided to register and ask in case someone is willing to help me.
#include <iostream>
#include <string.h>
#include <stdlib.h>
using namespace std;
class usuario {
private :
string username[10], password[10];
int aux;
public :
usuario();
void setUnamep(string, string, int);
string getUnamep();
void setPass(string);
string getPass();
int DataAcc(string, string);
~usuario();
};
class moneda {
protected :
float cantidad;
public :
moneda(float);
void setCant(float);
void getCant();
~moneda();
};
class bitcoin : public moneda {
private :
float btc[20];
public :
bitcoin (float);
void setBuy(float, float[]);
void getBuy();
void mostrarc(float);
~bitcoin();
};
usuario::usuario () {
}
void usuario::setUnamep(string username_, string password_, int aux_) {
string PreUser[20], aux_2;
aux = aux_;
for (int i= 1; i <= aux; i++) {
username[i] = username_[i];
password[i] = password_[i];
cout<<"\nEnter an username: ";
cin>>username[i];
cout<<"Enter a password: ";
cin>>password[i];
username[0] = "."; //pass 1 leer
for (int v = 0 ; v < i; v++) {
if (username[v] == username[i]) {
cout<<"\nUsername already in use. Choose another"<<endl;
username[i] = "null";
password[i] = "null";
i--;
v = 20000;
}
}
}
}
int usuario::DataAcc(string InUs, string InPass) {
bool ing = false, ret = false;
int u = 0;
do {
if (InUs==username[u] and InPass==password[u]) {
ing = true;
u = 10;
ret = true;
}
else //////
u++;
}
while (ing == false and u<5);
if (u == 5)
cout<<"\nIncorrect user or password. Try again."<<endl;
if (ing == true) {
cout<<"\nAccount data..."<<endl;
}
return ret;
}
usuario::~usuario() {
}
moneda::moneda(float cantidad_) {
cantidad = cantidad_;
}
moneda::~moneda() {
}
bitcoin::bitcoin(float cantidad_) : moneda(cantidad_) {
}
void bitcoin::setBuy(float cantidad_, float btc_[]) {
int aux;
for (int i = 0; i < 20 ; i++) {
btc[i] = btc_[i];
}
cout<<"How many BTC do you wish to buy?: ";
cin>>cantidad;
btc[aux] = btc[aux] + cantidad;
}
bitcoin::~bitcoin() {
}
int main() {
int opc = 0, aux1;
string InUs, InPass;
int aux2 = 0;
bitcoin b1(0);
cout<<"Welcome to BitZuela 2018, down there you have several options for you to choice which one do you want to run. ";
cout<<"\n\n1. Sign Up."<<endl;
cout<<"2. Log in."<<endl;
cout<<"3. Finish program."<<endl;
usuario u1;
while (opc >=0 and opc <=2) {
cout<<"\nPress the button of the option you want to run: ";
cin>>opc;
if (opc==1) {
cout<<"\nHow many accounts do you want to register?: ";
cin>>aux1;
u1.setUnamep("null", "null", aux1);
}
if (opc==2) {
cout<<"\nUsername: ";
cin>>InUs;
cout<<"Password: ";
cin>>InPass;
aux2 = u1.DataAcc(InUs, InPass);
if (aux2 == 1) {
b1.setBuy(0,0); //The problem is when this object is created
}
}
if (opc == 3)
cout<<"\nProgram finished."<<endl;
}
return 0;
}
That's it, I would be very grateful if someone can help me solving this problem. Also, if you have a suggestion about another thing, It'll be a pleasure to read it!
There seems to be some trouble with this method
void bitcoin::setBuy(float cantidad_, float btc_[]) {
int aux;
for (int i = 0; i < 20 ; i++) {
btc[i] = btc_[i];
}
cout<<"How many BTC do you wish to buy?: ";
cin>>cantidad;
btc[aux] = btc[aux] + cantidad;
}
The 'aux' variable is used before it is set resulting in undefined behavior.
Also the call is passing a 0 instead of a float[]. The compiler interprets the 0 as a nullptr, resulting a crash in ::setBuy
if (aux2 == 1) {
b1.setBuy(0,0);
Probably some other issues but fixing these will be a step in the right direction
Your core dumped is in the setBuy function. You ask for an array of float, but when you call it in your code, you pass a "0", but you should pass an array of 20 elements.
The aux variable is set inside the function, but I think you should pass it from the signature of the function.
Also, the cantidad variable that you are using inside that function is not the one in the signature (you should remove it from the signature, or add an _ to cantidad).
I also looked into your setUnamep function, you should use an std::map for your username and password management (You can search for an already existing keys in log(n)).
import javax.swing.JOptionPane;
public class sam{
public static void main(String[]args){
String a;
String b;
int c;
sam s1 = new sam();
a=s1.getInfo();
c=s1.getBalance();
b=s1.getMenu(a,c);
}
//menu method starts here
public String getMenu (String c, Integer d) {
String[] a;
String[] choices = { "Account Balance", "Deposit", "Withdraw", "User Account", "Exit options"};
String input = (String) JOptionPane.showInputDialog(null, "What would you like to do?",
"ATM menu", JOptionPane.QUESTION_MESSAGE, null,choices,choices[0]);
if ((choices[0] == choices[0])){
JOptionPane.showMessageDialog(null,"Your Account Balance is: "+d,"ATM machine",JOptionPane.INFORMATION_MESSAGE);}
//the if statement is executing properly
else if ((choices[1] == choices[1])){
String in=JOptionPane.showInputDialog("Deposit: ");
int deposit=Integer.parseInt(in);
int add=d+deposit;
JOptionPane.showMessageDialog(null,"Your Current Balance: "+add,"ATM machine",JOptionPane.INFORMATION_MESSAGE);}
//but when I chose account balance it displays the if statement not the else-if one
else if ((choices[2] == choices[2])){
String in=JOptionPane.showInputDialog("Withdraw: ");
int withdraw=Integer.parseInt(in);
int sub=d+withdraw;
JOptionPane.showMessageDialog(null,"Your Current Balance: "+sub,"ATM machine",JOptionPane.INFORMATION_MESSAGE);}
else if ((choices[3] == choices[3])){
JOptionPane.showMessageDialog(null," "+c,"ATM machine",JOptionPane.INFORMATION_MESSAGE);}
else if ((choices[4] == choices[4])){
JOptionPane.showMessageDialog(null,"The program will be terminated in a few seconds","ATM machine",JOptionPane.INFORMATION_MESSAGE);
}
return input;
}
//I'm quite new to programming, I rushed coded it for finals.
All of your if statements will evaluate to true. I think your intentions were to compare String c with each of the Strings in the choices array.
When comparing Strings always use .equals() not ==.
Example:
if (c.equals(choices[0])) {
// code
} else if (c.equals(choices[1])) {
//code
} else if (c.equals(choices[2])) {
// code
}
class Seller
{
private:
float salestotal; // run total of sales in dollars
int lapTopSold; // running total of lap top computers sold
int deskTopSold; // running total of desk top computers sold
int tabletSold; // running total of tablet computers sold
string name; // name of the seller
Seller::Seller(string newname)
{
name = newname;
salestotal = 0.0;
lapTopSold = 0;
deskTopSold = 0;
tabletSold = 0;
}
bool Seller::SellerHasName ( string nameToSearch )
{
if(name == nameToSearch)
return true;
else
return false;
}
class SellerList
{
private:
int num; // current number of salespeople in the list
Seller salespeople[MAX_SELLERS];
public:
// default constructor to make an empty list
SellerList()
{
num = 0;
}
// member functions
// If a salesperson with thisname is in the SellerList, this
// function returns the associated index; otherwise, return NOT_FOUND.
// Params: in
int Find ( string thisName );
void Add(string sellerName);
void Output(string sellerName);
};
int SellerList::Find(string thisName)
{
for(int i = 0; i < MAX_SELLERS; i++)
if(salespeople[i].SellerHasName(thisName))
return i;
return NOT_FOUND;
}
// Add a salesperson to the salespeople list IF the list is not full
// and if the list doesn't already contain the same name.
void SellerList::Add(string sellerName)
{
Seller(sellerName);
num++;
}
I have some issues with the parameters in my functions in my SellerList class. I want to add someone to the salespeople array so I have a record of all my sellers... Bob, Pam, Tim, etc... My constructor Seller(sellerName) creates a Seller with name sellerName.
How do I add this Seller to the Salespeople array and have capability of a way to pull the data back out and use it in more functions such as a Update function, or an output function?
MAX_SELLERS = 10.... I guess my issue is not knowing whether to use parameters of only
Add(string) or Add(Seller, string). Any help would be appreciated.
Not reinvent the wheel. Choose the container appropiate to your problem. In this case, because you are referencing/searching Sellers by a std::string, I suggest you to use a hash table like std::unordered_map (Or std::map search tree if you don't have access to C++11):
int main()
{
std::unordered_map<Seller> sellers;
//Add example:
sellers["seller name string here"] = /* put a seller here */;
//Search example:
std::unordered_map<Seller>::iterator it_result = sellers.find( "seller name string here" );
if( it_result != std::end( sellers ) )
std::cout << "Seller found!" << std::endl;
else
std::cout << "Seller not found :(" << std::endl;
}
How about using STD vector inside of SellerList instead of the array.
vector<Seller> x;
you can do x.push_back(Seller(...)) or x[0].SellerHasName() and x.size() will give you the number of sellers.
maybe something like this?
// Add a salesperson to the salespeople list IF the list is not full
// and if the list doesn't already contain the same name.
void SellerList::Add(string sellerName)
{
if(num < MAX_SELLERS)
salespeople[num++] = new Seller(sellerName);
}