Differences between matrix implementation in C
- by tempy
I created two 2D arrays (matrix) in C in two different ways.
I don't understand the difference between the way they're represented in the memory, and the reason why I can't refer to them in the same way:
scanf("%d", &intMatrix1[i][j]); //can't refer as &intMatrix1[(i * lines)+j])
scanf("%d", &intMatrix2[(i * lines)+j]); //can't refer as &intMatrix2[i][j])
What is the difference between the ways these two arrays are implemented and why do I have to refer to them differently?
How do I refer to an element in each of the arrays in the same way (?????? in my printMatrix function)?
int main()
{
int **intMatrix1;
int *intMatrix2;
int i, j, lines, columns;
lines = 3;
columns = 2;
/************************* intMatrix1 ****************************/
intMatrix1 = (int **)malloc(lines * sizeof(int *));
for (i = 0; i < lines; ++i)
intMatrix1[i] = (int *)malloc(columns * sizeof(int));
for (i = 0; i < lines; ++i)
{
for (j = 0; j < columns; ++j)
{
printf("Type a number for intMatrix1[%d][%d]\t", i, j);
scanf("%d", &intMatrix1[i][j]);
}
}
/************************* intMatrix2 ****************************/
intMatrix2 = (int *)malloc(lines * columns * sizeof(int));
for (i = 0; i < lines; ++i)
{
for (j = 0; j < columns; ++j)
{
printf("Type a number for intMatrix2[%d][%d]\t", i, j);
scanf("%d", &intMatrix2[(i * lines)+j]);
}
}
/************** printing intMatrix1 & intMatrix2 ****************/
printf("intMatrix1:\n\n");
printMatrix(*intMatrix1, lines, columns);
printf("intMatrix2:\n\n");
printMatrix(intMatrix2, lines, columns);
}
/************************* printMatrix ****************************/
void printMatrix(int *ptArray, int h, int w)
{
int i, j;
printf("Printing matrix...\n\n\n");
for (i = 0; i < h; ++i)
for (j = 0; j < w; ++j)
printf("array[%d][%d] ==============> %d\n, i, j, ??????);
}
