I have problems with this program. The idea is to read strings from text file and include them in 2D dynamic array with constant number of columns and varying number of ... |
I want to create a dynamic 2d array by function but it seems that something is very wrong. It throws me an error when I want to put something in it.
Error
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gprof is not working properly on my system (MinGW) so I'd like to know which one of the following snippets is more efficient, on average.
I'm aware that internally C compilers convert ... |
I am trying to workout a solution for this problem. The problem includes the following steps:-
- Dynamically allocate a 2D integer array A of size nXn (n is in the power of ...
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While I am here, I just thought I'd ask if there is a recommended way of handling 2d dynamic arrays. I implement them using the following kind of code. ------------------------------------------------ int fname( int sizex, int sizey, |
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Hello I have this code [HTML] string **a; //pointer to pointer to a string int x=300; int y=500; a=new string*[x] //Allocates first dimension for(int i=0;i &Arg) Also can you suggest ... |
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Must be something you've not posted, the code you have posted compiles for me without error. Perhaps you have a mismatched { or } BTW a common mistake that is made is that the internal data in a class has to match the external interface. By this I mean that you are implementing a 2D dynamic array so you have declared ... |
Hi everyone, I am new at programming. I was googling for how to create an 2d dynamic array. But I couldnt find what i want. I want to create an array which i will define during run time. For example i will say i want to input an array which is 2X3. But normally it should work for any size. And ... |
Hello All, I'm writing cross-platform code so i'm bound to standards. Here is the code I have: ~~~~~~~~~~~~~~~~~~ double **mx = new double*[col - 1]; for(int i = 0; i < col - 1; i++) { mx[i] = new double[row]; sizeOfMx += sizeof(double) * row; } //I need to fill "mx" with zeros as fast as it is possible ~~~~~~~~~~~~~~~~~~~ So ... |
monkeydragon schrieb:[color=blue] > #define MAX_TABLE = 1024; > BYTE* dynamic1D = new BYTE[SIZE]; > > later.. > > i want to create a dynamic 2d ARRAY like this: >[/color] Hi, int main () { int rows=10,cols=10; int** mat = new int*[rows]; for (int i=0; i |
struct solution { int ell; double array[5000][5000]; }; // now define 1200 of these structs struct solution *my_Sol; // doing the following return a NULL pointer. I am guessing there is no single // block of memory that big. I'd have to allocate smaller blocks like above // but the problem is the technique for 2d arrays deals with a single ... |
#include #include #include #include "lab03.h" int main(int argc, char **argv) { // check the No. of args if (argc != 4) { printf("No. of args should be 4!\n"); exit(0); } FILE *fptr; fptr = fopen(argv[1],"r"); if (fptr == NULL) { printf("Can not open file!\n"); exit(0); } int ROW, COL; ROW = atoi(argv[2]); COL = atoi(argv[3]); // call functions ... |
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Code: #define _GNU_SOURCE 1 #include #include #include #include #include #include #include typedef enum { FALSE = 0, TRUE = 1 } Bool; int main() { ssize_t readReturn = 0; size_t bufLen = 0; char **Inputs = NULL; char *input = NULL; int x = 0; Bool stillGoing = TRUE; int num_of_inputs = 0; int ... |
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unsigned char **twod; int x; twod = malloc( N * sizeof( unsigned char * ) ); for( x = 0; x < N; x++ ) twod[x] = malloc( M * sizeof( unsigned char ) ); ...do stuff with stuff... for( x = 0; x < N; x++ ) free( twod[x] ); free( twod ); |
hi, i'm anand & joining for the first time to any such forum sites. the program below 1. takes user input about the dimensions af the matrices 2. Checks whenther they are multiplicable 3. Dynamicall allocates memory to the matrices 4. Multiplies them and displays the resultant matrix with the original matices. hope this helps u. /* File name: Matmul.c */ ... |
Code: typedef struct BUTTON { short NoOfItems; char **Items; } BUTTON_COMPONENT; . . . for (i = 0; i < 3; i++) { if ((Button[i].Items = (char **) malloc (sizeof (char) * Button[i].NoOfItems)) == NULL) { ErrorMsg ("Button[i].Items is null!"); } else { if ((Button[i].Items[0] = (char *) malloc (sizeof (char) * (strlen ("First Button") + 1))) == NULL) { ErrorMsg ... |
There is no problem in accessing your example in that manner, however, I do have to point out that what you are working with is not a dynamic 2D array. A 2D array in C and C++ is guaranteed to occupy adjacent space in memory and is not an array of pointers to arrays. A more precise method of working with ... |
I am in the process of converting a C++ program to C and have run into a major problem with 2D dynamic arrays in C. The code I have posted below is just a test, but it does not work. What I am trying to do is read data from a file to figure out its dimensions (width and height) and ... |
#include #include void getdata(int **a){ int num_data=0,i; printf("Input the number : "); scanf("%d",&num_data); /* allocacate two D. */ a=(int **)malloc(num_data*sizeof(int*)); for(i=0 ; i |
I'm having a problem with creating a dynamic 2d array. What I want, is to be able to add strings to the "list" (Only add for now). The code that i've written fails on the second attempt to add a string. There's a memory leak somewhere, but i just can't understand it. I know i shouldn't use globals, but i just ... |
Code: #include #include #define ROWS 5 #define COLS 20 int main ( ) { int test[ROWS][COLS]; int **p; int row, col; /* allocate it */ p = calloc( ROWS, sizeof(int*) ); for ( row = 0 ; row < ROWS ; row++ ) { p[row] = calloc( COLS, sizeof(int) ); } /* use it */ for ( row = ... |
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Confused. Included files are copied into the source file (and substitutions for #defines are made, etc.) by the preprocessor before the compiler sees the result. This is true for each source file that has the file included. You should learn how and why files are organized. It has to do with the build process. The link provided above could be a ... |
First off, I made a test program for anyone willing to help. Basically all it does is statically declare a 2d char array, put in some numbers (char's.. not int's) and sorting it. Now this all works perfectly.. but when I try to do the exact same thing with a dynamically allocated 2d array it doesn't work.. This is the code: ... |
Hello Everyone, I am trying to read the data from a file and store into a 2D array(the file contains 540000 values), but i m facing memory issues. Then my friend suggested to create a dynamic 2D array, i thought thats simple but when i searched for the code on web, i was in vain and hardly implement those stuff. Can ... |
hi all, The way to dynamically allocate a 2D array is : int a(*)[5]; a=(int (*)[5])malloc(sizeof(int)*5); This will create array of pointer to arrays. We can access elements as a 2D array a[1][1] with access particular element. Question: 1. After allocating space for pointers, is it not the case that i need to allocate space for the array they are pointing ... |
Hi All, I'm working on an assignment and I need to create a 2D array of ints that is made up of memory that is all contiguous. Basically, I'm only allowed to call malloc() once and during that one call i need to allocate enough space for the entire 2D array. I understand that if i want an array with the ... |
I believe that the following code is correct for creating a dynamic 2d array K(which is a **int) : int **K; int n; /* Create a pointer to each row of the matrix. */ K = (int **)malloc(size * sizeof(int *)); /* Create each row of the matrix */ for(n = 0; n < size; n++) K[n] = (int *)malloc(size * ... |
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