I don't why it gives me l and col as undeclared inside this function.
I had written srand(time(null)) in main and I have already used rand in other variable in main and in this function, it's the second time using it.
void joueur_ordinateur(char jeton, int *a) {
srand(time(NULL));
do {
int l = rand() % 9;
int col = rand() % 9;
} while (matrice[l][col] == '.');
matrice[l][col] = jeton;
for (int i = 0; i < DIMENSION; i++) {
for (int j = 0; j < DIMENSION; j++)
copie[i][j] = matrice[i][j];
}
for (int i = 0; i < DIMENSION; i++) {
for (int j = 0; j < DIMENSION; j++) {
capture_chaine(i, j, jeton, a);
}
}
printf("\n");
}
don't why it gives me l and col as undeclared inside this function.
l, col only exist within the do block.
do {
int l = rand() % 9;
int col = rand() % 9;
} while (matrice[l][col] == '.');
Define l, col at the function beginning.
void joueur_ordinateur(char jeton, int *a) {
srand(time(NULL));
int l, col;
do {
l = rand() % 9;
col = rand() % 9;
} while (matrice[l][col] == '.');
Given "I had written srand(time(null)) in main", no needed for it in joueur_ordinateur().
void joueur_ordinateur(char jeton, int *a) {
// srand(time(NULL));
int l, col;
...
Related
I'm trying to write a code in C that sum two 4x4 matrix.
But I want my function to have a pointer as my arguments. The only error I'm getting is the time I'm trying to sum up in the function. Could someone help me?
#include <stdio.h>
#include <locale.h>
int i = 0, j = 0;
void calc_soma(int* mat_A, int* mat_B, int* mat_C)
{
for (i = 0; i < 4; i++)
{
for (j = 0; j < 4; j++)
{
mat_C[i][j] = mat_A[i][j] + mat_B[i][j];
printf("%d", mat_C[i][j]);
}
}
}
int main()
{
setlocale(LC_ALL, "Portuguese");
int i=0, j=0;
int mA[4][4], mB[4][4], mC[4][4];
int *mat_A, *mat_B, *mat_C;
for(i = 0; i < 4; i++)
{
for (j = 0; j < 4; j++)
{
printf("Type in the value for Matrix A [%d][%d]: ", i, j);
scanf_s("%d", &mA[i][j]);
}
}
i, j = 0;
for (i = 0; i < 4; i++)
{
for (j = 0; j < 4; j++)
{
printf("Type in the value for Matrix B [%d][%d]: ", i, j);
scanf_s("%d", &mB[i][j]);
}
}
*mat_A = &mA;
*mat_B = &mB;
return 0;
}
The types of pointers for the arguments are wrong. You want to pass (the pointer to the first elements of) arrays like int mA[4][4];, so they should be pointers to int[4].
void calc_soma(int (*mat_A)[4], int (*mat_B)[4], int (*mat_C)[4])
{
/* same as original */
}
They can simply be written like this:
void calc_soma(int mat_A[][4], int mat_B[][4], int mat_C[][4])
{
/* same as original */
}
Then the function can be called like:
calc_soma(mA, mB, mC);
The purpose of mat_A and mat_B are unclear, but if you want to get pointers to the matrice like &mA, it should be int(*)[4][4]. Note that dereferencing (like *mat_A) uninitialized pointers will invoke undefined behavior.
int main()
{
setlocale(LC_ALL, "Portuguese");
int i=0, j=0;
int mA[4][4], mB[4][4], mC[4][4];
int (*mat_A)[4][4], (*mat_B)[4][4], (*mat_C)[4][4];
/* omit */
mat_A = &mA;
mat_B = &mB;
return 0;
}
To use functions like
void calc_soma(int* mat_A, int* mat_B, int* mat_C)
you should express the matrice by 1D array to match with the format. It will be like this:
#include <stdio.h>
#include <locale.h>
#define ROWS 4
#define COLS 4
int i = 0, j = 0;
void calc_soma(int* mat_A, int* mat_B, int* mat_C)
{
for (i = 0; i < ROWS; i++)
{
for (j = 0; j < COLS; j++)
{
mat_C[i * COLS + j] = mat_A[i * COLS + j] + mat_B[i * COLS + j];
printf("%d", mat_C[i * COLS + j]);
}
}
}
int main()
{
setlocale(LC_ALL, "Portuguese");
int i=0, j=0;
int mA[ROWS * COLS], mB[ROWS * COLS], mC[ROWS * COLS];
for(i = 0; i < ROWS; i++)
{
for (j = 0; j < COLS; j++)
{
printf("Type in the value for Matrix A [%d][%d]: ", i, j);
scanf_s("%d", &mA[i * COLS + j]);
}
}
i, j = 0;
for (i = 0; i < ROWS; i++)
{
for (j = 0; j < COLS; j++)
{
printf("Type in the value for Matrix B [%d][%d]: ", i, j);
scanf_s("%d", &mB[i * COLS + j]);
}
}
calc_soma(mA, mB, mC);
return 0;
}
I know that object oriented is not welcoming in c language but I still trying to work my way because it is possible as later languages based on c works good with objects
so my question is when I try to write a function outside of main it doesnt give me access and doesnt change values of wanted structs , see code below (I marked every things and included working functions inside the main) :
#include <stdio.h>
#include <stdlib.h>
static int RandomNum() {
int generate = rand() / 100000000;
while (generate >= 9) {
generate = rand() / 100000000;
}
return generate;
}
// Object Definition
typedef struct {
int a, b;
int Mat[2][4];
} Matrix2x4;
typedef struct {
int a, b;
int Mat[4][5];
} Matrix4x5;
typedef struct {
int a, b;
int Mat[4][5];
} Matrix2x5;
void PrintMat2x4(Matrix2x4 a) {
int row = a.a;
int col = a.b;
for (int i = 0; i < row; i++) {
printf("{%s", " ");
for (int j = 0; j < col; j++) {
printf("%d ,", a.Mat[i][j]);
}
printf("}%s\n", " ");
}
}
void PrintMat4x5(Matrix4x5 a) {
int row = a.a;
int col = a.b;
for (int i = 0; i < row; i++) {
printf("{%s", " ");
for (int j = 0; j < col; j++) {
printf("%d ,", a.Mat[i][j]);
}
printf("}%s\n", " ");
}
}
void PrintMat2x5(Matrix2x5 a) {
int row = a.a;
int col = a.b;
for (int i = 0; i < row; i++) {
printf("{%s", " ");
for (int j = 0; j < col; j++) {
printf("%d ,", a.Mat[i][j]);
}
printf("}%s\n", " ");
}
}
// NOT WORKING AS A SEPERATE FUNCTION SO I PUT IT INSIDE THE MAIN
/*static void MatrixMultiplication (Matrix2x4 a , Matrix4x5 b , Matrix2x5 c) {
for (int i = 0; i < a.b; i++){
for (int j = 0; j < b.b; j++){
for (int k = 0; k < a.b; k++){
c.Mat[i][j] = c.Mat[i][j]+(a.Mat[i][k]*b.Mat[k][j]);}}}
}
void setRandom (Matrix a) {
int row = ((int)(sizeof (a.Mat) / sizeof (a.Mat)[0])) ;
int col = ((int)(sizeof (a.Mat)[0] / sizeof (a.Mat)[0][0])) ;
for (int i = 0; i < row ; i++){
for (int j = 0; j < col; j++){
a.Mat[i][j] = RandomNum();}}}*/
void main() {
printf("%s\n\n", "Start..");
Matrix2x4 test = {2,4,{0}}; // <----- SIZE IS 2X4
int row = ((int)(sizeof(test.Mat) / sizeof(test.Mat)[0]));
int col = ((int)(sizeof(test.Mat)[0] / sizeof(test.Mat)[0][0]));
for (int i = 0; i < row; i++) {
for (int j = 0; j < col; j++) {
test.Mat[i][j] = RandomNum();
}
}
Matrix4x5 test2 = {4,5,{0}}; // <----- SIZE IS 4X5
int row2 = ((int)(sizeof(test2.Mat) / sizeof(test2.Mat)[0]));
int col2 = ((int)(sizeof(test2.Mat)[0] / sizeof(test2.Mat)[0][0]));
for (int i = 0; i < row2; i++) {
for (int j = 0; j < col2; j++) {
test2.Mat[i][j] = RandomNum();
}
}
Matrix2x5 mult = {2,5,{0}}; // <----- SIZE IS 2X5
PrintMat2x4(test);
printf("X\n");
PrintMat4x5(test2);
printf("=\n");
for (int i = 0; i < test.b; i++) {
for (int j = 0; j < test2.b; j++) {
for (int k = 0; k < test.b; k++) {
mult.Mat[i][j] = mult.Mat[i][j] + (test.Mat[i][k] * test2.Mat[k][j]);
}
}
}
PrintMat2x5(mult);
printf("\n\n%s", "End ---> ");
}
In order for this function to work:
static void MatrixMultiplication (Matrix2x4 a , Matrix4x5 b , Matrix2x5 c) {
for (int i = 0; i < a.b; i++){
for (int j = 0; j < b.b; j++){
for (int k = 0; k < a.b; k++){
c.Mat[i][j] = c.Mat[i][j]+(a.Mat[i][k]*b.Mat[k][j]);}}}
}
You must pass your structs as pointers:
static void MatrixMultiplication (Matrix2x4* a , Matrix4x5* b , Matrix2x5* c) {
for (int i = 0; i < a->b; i++){
for (int j = 0; j < b->b; j++){
for (int k = 0; k < a->b; k++){
c->Mat[i][j] = c->Mat[i][j]+(a->Mat[i][k]*b->Mat[k][j]);}}}
}
Your original function doesn't work outside of main, because C is making a copy of those structs for the function's own use. Therefore the original structs never get modified. Changing those parameters to pointers means that the function is working with the original structs.
i need to use 'void lotto_gen(void)' function but i don't know how to make this => lotto[i + (j * 5)] = lotto_gen(); right. output should look like this picture enter image description here
#include<stdio.h>
#include<stdlib.h>
#include<time.h>
void lotto_gen()
{
int ball = 1 + rand() % 45;
}
void swap(int* a, int* b)
{
int r;
r = *a;
*a = *b;
*b = r;
}
void shuffle(int* arr, int size)
{
int i, r;
for (i = 0; i < size; i++)
{
r = rand() % (size - i) + i;
swap(arr + i, arr + r);
}
}
int main(void)
{
int i, j;
int lotto[50] = { 0 };
int size = sizeof(lotto) / sizeof(lotto[0]);
srand(time(0));
for (j = 0; j < 10; j++)
{
for (i = 0; i < 5; i++)
lotto[i + (j * 5)] = lotto_gen();
}
for (j = 0; j < 10; j++)
{
printf("[");
for (i = 0; i < 5; i++)
printf("%d ", lotto[i + (j * 5)]);
printf("]\n");
}
return 0;
}
From your comment, "It states that the problem does not require parameters in lotto_gen()" -- If this is only the problem constraint, then you have your freedom to choose the return type. Why not go with int lotto_gen(void) instead of void lotto_gen(void). You can have your lotto_gen() function like this:
/* ..... */
int lotto_gen(void)
{
return (1 + rand() % 45);
}
/* .... */
Well i m struggling with the pointers, why doesn t work the function biggest in the end (yes of that s dummy function)? (exit code 6)
Ty for help
code:
int search(int const a[], int n, int key) {
for (int *i = a; i < a + n; i++) {
if ( key == *i ) return 1;
}
return 0;
}
void print_row(int const a[], int n, int row) {
for (int *i = a + n * row; i < a + n * (row + 1); i++) {
printf("%d ", *i);
}
printf("\n");
}
void biggest(double x, long *int_part, double *frac_part) {
*int_part = (long) x;
*frac_part = x - *int_part;
}
main () {
int tempretures[7][24];
for (int *i = &tempretures[0][0]; i < &tempretures[7][24]; i++) {
static int j = 1;
*i = j;
j+=2;
}
tempretures[6][5] = 32;
for (int i = 0; i < 7; i++) {
for (int j = 0; j < 24; j++) {
printf("%d ", tempretures[i][j]);
}
printf("\n");
}
printf("Is it: %d\n", search(tempretures, 7*24, 32));
for (int i = 0; i < 7; i++) {
print_row(tempretures, 24, i);
}
long a = 0; double b = 0;
biggest(5.67, &a, &b);
printf("%li", a);
}
for (int *i = &tempretures[0][0]; i < &tempretures[7][24]; i++) {
static int j = 1;
*i = j;
j+=2;
}
This runs way past the end of the array, stopping only when it hits every element of row number 7, but there is no row number 7.
I'm trying to create and print a matrix, but I'm getting segmentation fault.
int** init_dynamic_matrix (int l, int c);
void print_dynamic_matrix (int** ppints, int l, int c);
int main ()
{
int** ppints = NULL;
int l = 6, c = 3;
ppints = init_dynamic_matrix (l, c);
print_dynamic_matrix (ppints, l, c);
return 0;
}
int** init_dynamic_matrix (int l, int c)
{
int i = 0, j = 0;
int** ppaux = NULL;
ppaux = (int**) malloc (l * (sizeof (int*)));
for (i = 0; i < l; i++)
{
*(ppaux + i) = (int*) malloc (c * (sizeof (int)));
for (j = 0; j < c; j++)
{
ppaux[l][c] = 0;
}
}
return ppaux;
}
void print_dynamic_matrix (int** ppints, int l, int c)
{
int i = 0, j = 0;
for (i = 0; i < l; i++)
{
for (j = 0; j < c; j++)
{
printf ("%d", ppints[l][c]);
}
printf("\n");
}
}
for (j = 0; j < c; j++)
{
ppaux[l][c] = 0;
}
Here's the error: in the first iteration of the outer for loop you will execute this , but ppaux[l] is not yet initialized, so you get segmentation fault.
You probably meant something like:
for (j = 0; j < c; j++)
{
ppaux[i][j] = 0;
}
Because you just created the i-th row of your matrix and you want to se it to 0