My for loop doesn't work?

I'm creating a program that solves linear systems using the Gauss-Jordan method by following this algorithm:

for each row ri of the matrix (i from 1 to n)
        replace ri with ri / rii
        for each row rk of the matrix (k!=i)
                replace rk with rk - rki * ri

Apparently I'm not doing it right because only th开发者_如何学Goe first element in the row is being divided by itself. I'm still new to C, so any help would be appreciated. Thanks!

for (k = 0; k < n; k++) {
    for (m = 0; m < n+1; m++) {
        if (matrix[k][m] < TOLERANCE) {
            printf("Error, pivot is 0\n");
            exit(0);
        }
        matrix[k][m] = matrix[k][m] / matrix[k][k];
    }

    for (l = 0; l != k; l++) {
        printMatrix(n, n+1, matrix);
        for (o = 0; o < n+1; o++) {
            matrix[l][o] = matrix[l][o] - matrix[l][k] * matrix[k][o];
        }
    }
}

Any other input? It's still not quite right and I'm pulling my hair out lol

For a start, the l != k in your inner loop is a continue condition. In other words, that loop will exit when l is equal to k.

That's not how it works in the original code. It keeps going for all other values of l.

You can use something like this instead:

for(l = 0; l < n; l++) {
    if (l != k) {
        printMatrix(n, n+1, matrix);
        for (o = 0; o < n+1; o++) {
            matrix[l][o] = matrix[l][o] - matrix[l][k] * matrix[k][o];
        }
    }
}

And, as an aside, you should probably try to move away from one-letter variable names, especially l, which can bite you quite badly the first time you mistake it for 1 :-)

You will be dividing matrix[k][k] by itself (thus setting it to 1) and then dividing the rest of the row by 1. Use a temporary variable to store the original pivot instead of using matrix[k][k]

Edit: While the above is a bug in the code, that's probably not causing what you are experiencing, as others have pointed out, you also need to use continue, rather than terminating the loop when l=k.

You should replace

for(l = 0; l != k; l++){

with

for(l = 0; l < n; l++){
  if (l == k) continue;

The first one stops as soon as l reaches k, so only processes rows 0..k-1. The second one processes rows 0..n-1 except row k (which fits to your pseudocode "for each row rk of the matrix (k!=i)")

Also:

for(m = 0; m < n+1; m++){

This means you have a matrix with n rows and n+1 columns, is this correct? If it is, everything else looks good as far as I can say.