# ALGORITHM: parseSparse (M) // M is the given matrix

    //first, we "incrementally" parse the matrix
    //this enables us to capture only non-zero entries
    //of each row.

    set sum = 0;

    foreach $row{
        foreach $col{
            if M($row, $col) != 0
                $key = concatenate ($row, $col);
                $hash{$key} = M($row, $col);
        }
    }

    //now that my hash is ready, I can do random access faster

    /* implement what you want to implement, I will just sum all the non zero elements of M */

    foreach $key (keys %hash) {
      sum += $hash{$key};
    }