Im trying to shuffle my deck of cards using pointers. My loops just print out the default value, not cycling through the cards. how do i fix this. shuffle functiuon is at the bottom? I am trying to loop through and increment pointers while replacing my destination pointer with my source pointer. or the dereferenced value. what am i doing wrong?
#include <iostream>
#include <fstream>
#include <ctime>
#include <stdlib.h>
#include <string>
using namespace std;
//global constant(s)
const int maxCards = 52;
//Structs
struct card
{
char suit[8];
char rank[6];
int cvalue;
char location;
};
struct player
{
char name[100];
int total;
};
//Function List
char * strcopy(char destination[], const char source[]);
void shuffle(card* destinationP,card* sourceP);
//program
int main()
{
//begin seeding the time for randomize later
srand(time(NULL));
//declaration of variables
bool gameOn =true;
int choice;
char tempfName[100];
char templName[100];
int count =0;
//create struct array(s)
card deck[52];
card shuffledDeck[52];
player people[4];
//create pointer and set initial value
card * deckPointer = NULL;
card * shuffledDeckPointer= NULL;
player *peoplePointer = NULL;
//
deckPointer = &deck[0]; //assign address of deck to deckPointer
shuffledDeckPointer = &shuffledDeck[0];
peoplePointer = &people[0]; //assign address of people to peoplePointer
//sets default values for the card arrays
for(int i=0;i<52;i++)
{
strcopy(shuffledDeck[i].suit, "suit");
strcopy(shuffledDeck[i].rank,"rank");
shuffledDeck[i].cvalue = 0;
strcopy(deck[i].suit,"suit");
strcopy(deck[i].rank,"rank");
deck[i].cvalue = 0;
}
//set up card file to be read in
ifstream fin;
char finName[12];
//get file name from user
cout << "Enter file name...(cardFile.txt)" << endl;;
cin >> finName;
//open the file
fin.open(finName);
//check if cardFile.txt opens correctly
if(!fin.good())
{
cout << "Error with card file" << endl;
return 0;
}
else
{
card *deckPointer = NULL;
//prime fin
//fin >> deck[i].suit;
//fin >> deck[i].rank;
//fin >> deck[i].cvalue;
while(fin.good())
{
for(deckPointer = &deck[0]; deckPointer < &deck[maxCards];deckPointer++)
{
fin >> (*deckPointer).suit;
fin >> (*deckPointer).rank;
fin >> (*deckPointer).cvalue;
}
}
}
cin.clear();
}
//Functions
//copy string function
char * strcopy(char *destination, const char* source)
{
char *p = destination;
while(*p++ = *source++);
return destination;
}
//Shuffle function
void shuffle(card *destinationP,card *sourceP)
{
int randomNumber = 0;
int count=0;
for(int j=0;j<52;j++)
{
//choose a random number up to 52
randomNumber = rand()%52;
count = 0;
if(count < randomNumber)
{
while(count < randomNumber)
{
*sourceP++;
count++;
}
//check if destination is empty ie will accept
//a card and will not overwrite a card
if((*destinationP).cvalue == 0)
{
// copy unshuffled "deck" to the shuffled "deck"
strcopy((*destinationP).suit, (*sourceP).suit);
strcopy((*destinationP).rank, (*sourceP).rank);
(*destinationP).cvalue = (*sourceP).cvalue;
*destinationP++;
}
}
else
{
if((*destinationP).cvalue == 0)
{
// copy unshuffled "deck" to the shuffled "deck"
strcopy((*destinationP).suit, (*sourceP).suit);
strcopy((*destinationP).rank, (*sourceP).rank);
(*destinationP).cvalue = (*sourceP).cvalue;
*destinationP++;
}
}}}
Just use an std::vector and std::shuffle. Also don't use rand(), use the <random> header instead. And std::string instead of char*.
I prefer the Fisher-Yeats shuffle which Donald Knuth put into his Art of Computer Programming as Algorithm P. Pseudo code can be found at: http://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle. Incidentally, for better randomization properties, I would recommend using a Mersenne Twister (http://en.wikipedia.org/wiki/Mersenne_Twister) for which you can find GPLd source in several languages
Related
I'm trying to read from the same file from another function but it doesn't work.
I guess the problem is that I'm trying to read from ifstream &input but I don't know the other way to implement that
#include <iostream>
#include <fstream>
using namespace std;
class Student{
public:
char name[40]; // i cant use string
int age;
void Input(ifstream &input)
{
input.getline(name, 40);
input >> age;
}
};
void Read(Student *students, int &numberOfStudents)
{
ifstream input("test.txt");
input >> numberOfStudents;
students = new Student[numberOfStudents];
for (int i = 0; i < numberOfStudents; ++i)
students[i].Input(input);
input.close();
}
int main()
{
int size = 0;
Student *students = NULL;
Read(students, size);
for (int i = 0; i < size; ++i)
cout << students[i].name << endl << students[i].age << endl;
return 0;
}
I made my input file
3
1
2
3
4
5
6
(if the program was working correctly i should've get 1 - name age - 2 etc)
but what i got is no names with ages = 1 2 3 respectively
The program does not work because you define:
void Read(Student *students, int &numberOfStudents)
And then
int size = 0;
Student *students = NULL;
Read(students, size);
The students pointer is passed-by value so Read() can not change the memory address outside the function.
To fix this simply pass the the pointer by-reference:
void Read(Student *& students, int &numberOfStudents)
Lastly as I commented you need to account white space e.g. '\n' line ending
In the file when using >> operator to extract data:
void Input(ifstream &input)
{
input.getline(name, 40);
input >> age;
input.ignore(1);
}
Same for reading the number of students in the file.
I'm writing a program in C++ where I take in a line from a txt file and stick it into a vector<string> data that is within a struct (I'm making a linked list of each individual line). Technically I have a loop set up that will break up the words from the sentence I'm taking in, and pushing them into the vector one by one.
The issue I've ran into is when I try getting the vector size via
int size;
size = current->data.size();
Current being a node. I get both an implicit conversion warning and a "Thread 1: EXC_BAD_ACCESS (code=EXC_I386_GPFLT)".
Can anyone explain where I am going wrong? Is it just not possible to code something like that? Should I just create a counter variable to keep track of how many words are being placed into the vector? And what would be the best programming practice to go about achieving this?
Here is my main() file
#include <iostream>
#include <fstream>
#include "SkipGram.hpp"
using namespace std;
int main() {
string file;
ifstream inFile;
vector<string> sentence;
string line;
SkipGram control;
int skip;
int gram;
cout << "Please enter file name:\n";
cin >> file;
inFile.open(file);
while(!inFile.is_open()){ //makes sure we get a working file
cout << "Error reading in file. Please try again.";
cin >> file;
inFile.open(file);
}
cout << "Please enter how many words you want skipped and the amount of grams:";
cin >> skip >> gram;
while(!inFile.eof()){
getline(inFile, line);
control.convert(line);
}
control.skipGramFunc(skip, gram);
control.printSkipGram();
return 0;
}
Here is my .hpp file
#include <stdio.h>
#include <iostream>
#include <vector>
#include <string>
using namespace std;
class SkipGram{
public:
SkipGram();
void convert(string line);
void skipGramFunc(int skip, int gram);
void printSkipGram();
private:
typedef struct sentence{
vector<string> data;
vector<string> result;
int position;
sentence* next;
}* sentencePtr;
sentencePtr first;
sentencePtr current;
int amount;
};
Here is my .cpp file
#include "SkipGram.hpp"
using namespace std;
SkipGram::SkipGram(){
first = NULL;
current = NULL;
amount = 0;
}
void SkipGram::convert(string line){
// go word by word through sentence and create a vector out of it
// add into the sentence list
sentencePtr newSentence = new struct sentence;
if(first == NULL){
current = newSentence;
first = newSentence;
amount++;
newSentence->position = amount;
}else {
current = newSentence;
amount++;
newSentence->position = amount;
}
string word;
int length = line.length();
int i = 0;
int front = 0;
int temp;
while( i <= length){
temp = line.find(" ");
if( temp == -1){
break; //catches when sentence is done with
}
word = line.substr(front, temp);
newSentence->data.push_back(word);
temp++;
line = line.erase(front, temp);
} //END OF WHILE
}
void SkipGram::skipGramFunc(int skip, int gram){
// goes through word vector and rearranges them
if(gram == 1){
cout << "Need more than one gram!" << endl;
return;
}
if(skip == 0 || gram == 0){
cout << "Input cannot be 0!";
}
int size;
int temp;
int tempAmount = amount;
current = first;
skip++;
while( tempAmount != 0){ // while loop goes through all the sentences
size = current->data.size();
size = size - skip; // size here essentially becomes a marker to find out where to stop the loop
for(int i = 0; i < size; i++){ // for loop goes through all the words
for(int j = 0; j < gram; j++){ // this loop checks to see if we got the right number of grams
if(j == 0){ // are we on the first gram
current->result.push_back(current->data.at(i));
}else { // we want skipped gram
temp = i + skip;
current->result.push_back(current->data.at(temp));
} // END OF IF
}// END OF GRAM IF
current->result.push_back(",");
}//END OF WORD FOR
current = current->next;
tempAmount--;
}//END OF WHILE
}// END OF FUNCTION
void SkipGram::printSkipGram(){
int tempAmount = amount;
current = first;
while(tempAmount != 0){
int size = current->data.size();
for(int i = 0; i <= size; i++){
cout << current->data.at(i);
};
}//END OF WHILE
}
You never assign to next, but you do read it. Whereupon your program exhibits undefined behavior by way of accessing a value of uninitialized object.
My name is Faith and I am a beginner programmer in C++. I am working on a project where I have to read in two file and be able to separate the items in each file to its own variable. The first file has two pieces of information separated by "," and the second has three pieces of information. So far, I think I've done well with reading the files and getting each line in the file. Also I've separated each item by "," now I am trying to store those items in its on variable. Please Help! I've tried starting this project over multiple times and this is the only method I know how to implement to do this.
#include <stdio.h>
#include <iostream>
#include <fstream>
#include <sstream>
#include <stdlib.h>
using namespace std;
class Manufactuer{
string upcode;
string company_name;
public:
void setupcode(string value){
upcode= value; }
void setcompany_name(string value){
company_name= value; }
string getupcode(){ return upcode;}
string getcompany_name(){return company_name;}
};
class Products{
string product_num;
string quantity;
string product_name;
public:
void setproduct_num(string value){
product_num= value; }
void setproduct_name(string value){
product_name= value; }
void setquantity(string value){
quantity = value;}
string getproduct_num(){ return product_num;}
string getquantity(){return quantity;}
string getproduct_name(){return product_name;}
};
int main(int argc, const char * argv[]) {
//opens the csv file
std::ifstream mccodesfile;
std::ifstream salesfile;
mccodesfile.open("mccodes.csv");
if(!mccodesfile){// file couldn't be opened
cout<<"Failed: file could not be opened"<<endl<<"Press Enter to Close:";
cin.get();
return 0;
}else
cout<<"Successfully opened file!"<<endl;
salesfile.open("sales.csv");
if(!salesfile){// file couldn't be opened
cout<<"Failed: file could not be opened"<<endl<<"Press Enter to Close:";
cin.get();
return 0;
}else
cout<<"Successfully opened file!"<<endl;
Manufactuer* upccodes;
int count; //how many elements in the array
int size; //how large the array
count = 0;
size = 2;
upccodes= (Manufactuer*)malloc(size*sizeof(Manufactuer)); //Malloc dynamatically reserve memory for variable pointer
string line;
while (getline(mccodesfile,line)) {// Taking every line from the file and putting in the variable line
Manufactuer newcode = Manufactuer(); //creating a upcode object
istringstream ss(line);
string token; //setting up split values
bool haveReadUPCode = false;
while (getline(ss,token,',')){// Separated values by comma
if(!haveReadUPCode){
newcode.setupcode(token);
haveReadUPCode = true;
}else{
newcode.setcompany_name(token);
}
}
if (count == size){
size = size * 2;
upccodes= (Manufactuer*)realloc(upccodes,size*sizeof(Manufactuer)); //Double the size while keeping the same elements
}
upccodes[count++]= newcode;
// cout<<line<<endl;
}
for (int i = 0; i<count; i++){
// cout<<upccodes[i].getcompany_name()<<endl; //Prints Manufactuers name--Works!
}
for (int i=0; i<count; i++) {
// cout<<upccodes[i].getupcode()<<endl; //Prints UPCcodes--Works
}
Products* product;
product= (Products*)malloc(size*sizeof(Products)); //Malloc dynamatically reserve memory for variable pointer
while(getline(salesfile, line)){{// Taking every line from the file and putting in the variable line
Products newProduct = Products(); //creating a product object
istringstream ss(line);
string token; //setting up split values
bool haveReadProduct = false;
while (getline(ss,token,',')){// Separated values by comma
if(!haveReadProduct){
newProduct.setproduct_num(token);
haveReadProduct = true;
} else{
newProduct.setproduct_name(token);
newProduct.setquantity(token);
}
}
if (count == size){
size = size * 2;
product= (Products*)realloc(product,size*sizeof(Products)); //Double the size while keeping the same elements
}
product[count++]= newProduct;
//cout<<line<<endl; //LINES ARE Printing!
}
}
for (int i = 0; i<count; i++){
// cout<<product[i].getproduct_name()<<endl; //Prints Product name--Works
}
for (int i = 0; i<count; i++){
//cout<<product[i].getproduct_num()<<endl; //Prints Product number--Works
}
}
I am getting a segmentation fault: core dumped error when I am reading in players file..
I am trying to add both "firstname lastname" to the player struct. I am trying to access the "0th" people and increment their name because i need both first and last, i cant simply fin >> people[i].name in a simply for loop as i do for the card value (not shown) "heart two 2" for example
// deck of cards
// below are initializations
#include <iostream>
#include <fstream>
#include <ctime>
#include <stdlib.h>
#include <string>
using namespace std;
//globals
const int maxCards = 52;
//Structs
struct card {
char suit[8];
char rank[6];
int cvalue;
char location;
};
struct player {
char name[];
int total;
card hand[];
};
//program
int main()
{
char tempfName[100];
char templName[100];
//create struct array(s)
card deck[52];
card shuffledDeck[52];
player people[4];
//set defalt values
for(int i=0;i<4;i++)
{
strcopy(people[i].name,"first last");
}
//open player names file
ifstream fin2;
string fin2Name;
//get file name from user
cout << "Enter player file name...(Players.txt)" << endl;
getline(cin,fin2Name);
fin2.open(fin2Name.c_str());
//check if Players.txt opens correctly
if(!fin2.good())
{
cout << "Error with player file!" << endl;
return 0;
}
else
{
int j =0;
//fin2 >> people[j].name; //prime file
while(fin2.good())
{
//find the length
int index =0, length=0;
while(tempfName[length] != '\0')
{
length++;
}
//now add space after first name
tempfName[length] = ' ';
length++;
while(templName[index] != '\0')
{
tempfName[length] = templName[index];
length++;
index++;
}
tempfName[length]='\0';
int counter =0;
while(templName[counter] != '\0')
{
people[0].name[counter] = templName[counter]; //testing program on "0th" people
counter++;
}
}
}
}
In your struct, name[] and hand[] are of undetermined size. It's hence difficult to read anything into them.
Then, once you've opened the stream, you're trying to determine the length of the unitianalized tempfName[]. This ain't no good: you're not sure it's null terminated and you'll go out of bounds ! This is the origin of your segfault.
Consider initalizing these by declaring them as:
char tempfName[100]{};
char templName[100]{};
Once this is fixed, your code still loops forever on while (fin2.good()) without reading anything, and bravely adding one whitespace to tempfName until you're out of bound.
Now suppose you'd fix all this, set a length to your name and undcomment your stream reading fin2 >> people[j].name; you'd still have a very risky situation: if the data would be longer that what you've foresseen, it would be truncated and the name wouldn't have a terminating '\0'.
Recommendation 1:
Consider using std::string instead of char[] whenever you consider storing a string. Example:
struct player {
string name = "first last" ; // initialisation value: no strcpy() needed !!
int total;
card hand[5]; // length ?
};
Recommendation 2:
Loop using your stream reading as loop condition:
while (fin2 >> people[j].name) { ///!!!
...
j++; // don't foget to increment your counter
}
However be carefull, because the >> will read one string at a time, the string ending at first whilespace (so only firstname).
If you adopt recommendation 1, it would be easy to write:
while (fin2 >> tempfName >> templName) { ///!!!
people[j++].name = tempfName + " " + templName;
}
which should perform pretty muchthe same thing that your loop, but with far less instructions and risks.
Recommendation 3:
If your number of players is fixed, define the max constant and use a for instead of a while to read your data:
const int max_player = 4;
player people[max_player];
...
for (j=0; j<max_player && (fin2 >> people[j].name); j++) // instead of the former while
If your limit of 4 was arbirary, consider using vectors. But that's another story for the moment.
Your struct player definition is not valid:
struct player {
char name[];
int total;
card hand[];
};
The C string fields name and hand need to have a length, e.g.
struct player {
char name[32];
int total;
card hand[32];
};
Your compiler should be giving you an error for this ("incomplete type").
Note also that since you are writing C++ code then it would be better to use std::string rather than C-style char * strings - it will be easier, more robust, and you won't be mixing C and C++ idioms.
I am trying to read in two words from text file into one char array element. I CANNOT USE std::string. I get a seg fault because my loop is looping in a way that goes out of bounds. I cannot copy in the two words. please help me do this!! My loop for card struct works perfectly. I cannot get the "first last" into the people[].name
// deck of cards
// below are initializations
#include
#include
#include
#include
#include
using namespace std;
//globals
const int maxCards = 52;
//Structs
struct card {
char suit[8];
char rank[6];
int cvalue;
char location;
};
struct player {
char name[100];
int total;
card hand[4];
};
//program
int main()
{
//constants
char tempfName[100];
char templName[100];
//create struct array(s)
card deck[52];
card shuffledDeck[52];
player people[4];
//create pointers
card * deckPointer =NULL;
deckPointer = deck;
card * shuffledDeckPointer=NULL;
shuffledDeckPointer = shuffledDeck;
for(int i=0;i<4;i++)
{
strcopy(people[i].name,"first last");
}
//open player names file
ifstream fin2;
string fin2Name;
//get file name from user
cout << "Enter player file name...(Players.txt)" << endl;
getline(cin, fin2Name);
//open file
fin2.open(fin2Name.c_str());
//check if Players.txt opens correctly
if(!fin2.good())
{
cout << "Error with player file!" << endl;
return 0;
}
else
{
int j =0;
fin2 >> people[j].name; //prime file
while(fin2.good())
{
//find the length
int index =0, length=0;
while(tempfName[length] != '\0')
{
length++;
}
//now add space after first name
tempfName[length] = ' ';
length++;
while(templName[index] != '\0')
{
tempfName[length] = templName[index];
length++;
index++;
}
tempfName[length]='\0';
int counter =0;
while(templName[counter] != '\0')
{
people[0].name[counter] = templName[counter];
counter++;
}
}
}
it seems your tempfName is not pointing to a correct object in your while loop in else statement
else
{
int j =0;
fin2 >> people[j].name; //prime file
while(fin2.good())
{
//find the length
int index =0, length=0;
while(tempfName[length] != '\0')
{
length++;
}
You could do some cheating:
char full_name[256]; // Binary quantities are better.
snprintf(full_name, sizeof(full_name),
"%s %s",
first_name, last_name);
You should do more research regarding C-style string functions, like check a good reference book. It should have a chapter about the C-style string functions.
Here are some helpful ones:
strcpy, strcat, strchr, sprintf, strlen