Question re: Pointers (I think)

[spiffwilkie]

This relates to an assignment, but I am not looking for answers (read the FAQ on that!)

I have written a program to multiply matrices, however, now that I re-read the specifications, I have a question.

I am supposed to implement a function as follows
void matmult(int m, int p, int n, float **a, float **b, float **c)

Well, I have a function like this:
void matmult(int m, int p, int n, float *a, float *b, float *c)

I've fiddled around with this thing, read plenty of articles, and searched, but I cannot grasp these pointers and other assorted nuances of C++. This is only my second program to write in the language and I'm a bit befuddled.

The algorithms are done, the program runs, I just need some nudges in the right direction regarding the function declaration.

Thanks,
Steve

[spiffwilkie]

Additionally, here is my code. Please feel free to rip it to pieces as I'm still new at C++

#include <cstdlib>
#include <iostream>
using namespace std;

void matpop(int m, int n, float *matToPop) {
    int i, j;
    float tempFlt = .0f;
    for (i = 0; i < m; i++) {
        for (j = 0; j < n; j++) {
            tempFlt = i * n + j;
            matToPop[i * n + j] = tempFlt;
        }
    }
}

void matmult(int m, int p, int n, float *a, float *b, float *c) {
    int i, j, k;

    for (i = 0; i < m; i++) {
        for (j = 0; j < n; j++) {
            float tempFlt = .0f;
            for (k = 0; k < p; k++) {
                tempFlt += a[i * p + k] * b[k * n + j];
            }
            c[i * n + j] = tempFlt;
        }
    }
}

void matprint(int m, int n, float *outputMat) {
    int i, j;
    for (i = 0; i < m; i++) {
        for (j = 0; j < n; j++) {
            float tmp = outputMat[i * n + j];
            cout << tmp << "\t";
        }
        cout << "\n";
    }
    cout << "\n";
}

int main(int argc, char** argv) {

    int m, p, n;
    cout << "Please enter the number of rows in array A: ";
    cin >> m;
    cout << "Please enter the number of columns in array A: ";
    cin >> p;
    cout << "Please enter the number of columns in array B: ";
    cin >> n;

    float a[m * p];
    float b[p * n];
    float c[m * n];

    matpop(m, p, a);
    matpop(p, n, b);

    matmult(m, p, n, a, b, c);

    cout << "The values for matrix A are:\n";
    matprint(m, p, a);
    cout << "The values for matrix B are:\n";
    matprint(p, n, b);
    cout << "The values for matrix C are:\n";
    matprint(m, n, c);

}

[TheJJJunk]

I cannot grasp these pointers

Check out

http://www.cdecl.org/

Its a website that translates c++ declarations into english. It's very useful for deciphering pointers.