So, guys, I'm in extreme doubt with the code below. I started to study pointers in C a few days ago and I believe it is the solution to my problem, but I do not know how to handle the code.
The problem is as follows. In the multiplyMatters () function I can not access the array C values obviously because it was declared inside the main. But the problem is that I can not declare it 'globally' off the main because I need to read the number of rows / columns of each array at the start of the program (I can not declare them in the code with a constant number of rows or columns).
Code:
#include<stdio.h>
#include<stdlib.h>
#define G 5
void lerMatrizes(int matrizX[][G], int matrizY[][G]);
void multiplicaMatrizes(int A[][G], int B[][G]);
int linhasA, colunasA, linhasB, colunasB;
int main() {
int i, j;
printf("\nInforme a quantidade de linhas da matriz A : ");
scanf("%d",&linhasA);
printf("\nInforme a quantidade de colunas da matriz A : ");
scanf("%d",&colunasA);
printf("\nInforme a quantidade de linhas da matriz B : ");
scanf("%d",&linhasB);
printf("\nInforme a quantidade de colunas da matriz B : ");
scanf("%d",&colunasB);
int valoresA[linhasA][colunasA], valoresB[linhasB][colunasB], valoresC[colunasA][linhasB];
lerMatrizes(valoresA, valoresB);
if (colunasA == linhasB) {
multiplicaMatrizes(valoresA, valoresB);
} else {
printf("\n\nNão é possivel multiplicar matrizes neste formato. O numero de colunasA tem que ser igual linhasB");
}
return 0;
}
void lerMatrizes(int matrizX[][G], int matrizY[][G]) {
int i, j;
// Gera Valores p Matriz1
for(i=0; i<linhasA; i++) {
for(j=0; j<colunasA; j++) {
matrizX[i][j] = i+1 * j+1;
}
}
// Gera Valores p Matriz2
for(i=0; i<linhasB; i++) {
for(j=0; j<colunasB; j++) {
matrizY[i][j] = i+1 * j+1;
}
}
}
void multiplicaMatrizes(int A[][G], int B[][G]) {
int i, j, k, temp=0;
for(i=0; i<colunasA; i++) {
for(j=0; j<linhasB; j++) {
valoresC[i][j]=0;
for(k=0; k<G; k++)
temp += A[i][k] * B[k][j];
valoresC[i][j] = temp;
temp=0;
}
}
}
I made the code using a constant number of rows / columns, then when I was changing it I caught this part there. I could not also pass the array by parameter, would the solution be a pointer?