keyinputter is an array of size 30. The first while loop finds the number of words in a file so that I can calloc the correct amount of space for the double pointer, keywords. The second while loop is supposed to read the words into the double pointer, but when I run a print statement to print the string at keywords[0], it only prints null and not the word. Am I assigning the strings to the double pointer in the wrong way?
const void insertStuff(const void *key, const int value){ // I want to convert the void pointer into one // of three types of pointers(int, string, or double) switch(value){ case 0: int *intPtr = key;
[Code] .....
But this causes an error of: "crosses initialization of int*intPtr"
I'm trying extract words from a text file and then put then them into a set. I want to delimit all the spaces as well as the periods. My code is working fine for spaces but its leaving out the periods at the end of some words.
Type two or more lines of text into a file. Write a program to open the file, reading each word into a vector<string> object. Iterate over the vector, displaying it to cout. That done, sort the words using the sort() generic algorithm
But I'm stuck unfortunately.
#include <iostream> #include<fstream> #include<vector> #include<cstdio> using namespace std; int main() { ifstream infile("about.txt");
I would like to store the titles of a CD and then read them. I have started a program but not sure how to display or make sure it is storing it in the .txt file.
I'm writing a program involving a theoretical hotel. Most of the code is already written, but the part I'm having trouble with involves the very beginning of the code.
The program is designed to read in from an input file the hotel's ID number, the types of rooms it has, the Room Numbers of each room, the base rate for each room, and the rate of additional charge per person.
The code demonstrates inheritance for my Object-Oriented Programming class, as each type of room will inherit from generic class Room, but I can't seem to figure out how to make the double-pointer for dynamic allocation work.
The code is below.
Hotel.h Code: class Hotel{ int hotelID; static const int MAX_SIZE = 101; Room **rPoint;
Am I assigning something the wrong way? Also, I am trying to avoid using array notation in order to practice, at least for the assigning of the strings.
I see that the function itself does not return anything but calls another function. The main difficulty I have is with the "dev->dev->" operator, where dev, I expect is a pointer to a structure.
I have int pointer called p and i want to calculate average.Since average involves using double or float so i am trying to convert this in the function averagetemp. It still gives me an error saying "cannot be converted"...
#include <iostream> using namespace std; int* createArray(int n); int lowesttemp(int *p,int f); int highesttemp(int *p,int f); double averagetemp(int *k,double f); void print(int *p,int lowest_temp,int highesttemp,int average_temp);
I am trying to read in player names (ex: first last) from a text file into the people[].name data struct. I can successfully read in my card file, but I cannot get this to work. I get a seg fault. I believe this is because nothing is actually being read in for my while loops. I can't use std::strings so these must be c-style strings aka char arrays.
// 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;
Why do most C examples pass a double pointer when manipulating linkedlists? Why can not we just pass a single pointer to the struct?I think using an external reference accessor for a linked list would be a more appropriate solution, yes or no?
The following code compiles and runs fine till it reaches line 16 and gets a sigsev violation which I'm not sure about as to why. I have no problem passing the object of type node** into the constructor of base and storing it into the double pointer node** copy;; but when I call the function void pass(node** temp) it crashes.
#include <iostream> class base; class node { private: node** data; public:
I was reading this earlier [URL] ..... and I was trying to figure out how to pick one of the words randomly from my text instead of using all the words in it.
I'm trying to read a "pointer-based" maze .txt. The first letter in each row corresponds to the room letter...then the letters that follow are North node, East node, South node, and West node respectively. The asterisk indicates an empty room or not a valid option.
Here is what I have come up with, what is happening is after the file is parsed by read_maze it is calling my is_empty function indicating that there is no maze because it doesn't go into the else statement here.
I've attached a sample input file:
maze.txt (130bytes) Number of downloads: 19
We can't assume the rooms will be in order alphabetically A - Z, We are expecting a maximum of 12 rooms and there is a space between each letter or asterisk.
void Maze::read_maze(string FileName){
string line; ifstream inStream; inStream.open(FileName.c_str()); int test = inStream.peek(); int i = 0; if (!(inStream.fail())){ while (!inStream.eof() && test != EOF){
I was having problems changing the value of my head node I passed it as an argument as head which would be the address. The parameter was defined as struct node *head. like this
I tried manipultaing pointer values to change head node value but it did not work. I saw some code online which used pointer to pointers(in code below) to change head node value it worked I dont fully understand why. Would like better understanding of why.
Would also like to know why the argument call needed &head instead of just head.
remove = deleteNode(&head,found); opposed to remove = deleteNode(head,found);
I have to write a program to print pascals triangle and stores it in a pointer to a pointer , which I am not entirely sure how to do. I also have to write the file and read it, then create a binary file. Assignment is attached. I am not the best with programming and especially with pointers. I will post my code below.
Code: #include <stdio.h> #include <stdlib.h> void writePascalTriangle(char *fileName, int heightOfTriangle, int **triangle) { FILE *fp; fp=fopen("writePascalTriangle.txt", "w");
I'm making a system like twitter for class called ShoutOut.com I want to be able to get the PublicShoutOut pointer pointed to by the start iterator and assign it to firstShoutOutToDisplay and secondShoutOutToDisplay because I need that in order to pass the pointers to one of my functions. When I step through the debugger the values in start are all default values like "" and so are the values in this->firstShoutOutToDisplay but the message that start points to is being output just fine.
EDIT: got rid of irrelevant code. Am I using the correct syntax to do this?
if (start != finish) { //getting these because a shoutout needs to be passed to the function that displays //options for a shoutout this->firstShoutoutToDisplay = (*start);
i have been fiddling with pointers but I don't understand how the proper syntax is written when I want to acces an element of an array through a pointer to a pointer...The code is all mostly just random bs for learning purposes. I marked the problem "// THIS LINE"
This is a sample program that declares a Matrix as a structure with an array as a pointer to a pointer. The following program is supposed to store a matrix in the structure "_Matrix" and later print the matrix just entered but it fails giving me a "segmentation fault". The sample code is given below
Code: #include <stdio.h> #include <stdlib.h> struct _Matrix { int row_size; int col_size; int **mat;
i really don't know why has a error in my code, that pass a pointer of pointer (name of a matrix with 2 dimensions). Here is the source code of a simple example where appears segmentation fault when execute (but compiles normal):
#include <stdio.h> #define LINHAS 3 #define COLUNAS 5 float a[LINHAS][COLUNAS]; void zeros(float **p,float m, float n){ int i,j; for(i=0;i<m;i++)
