graphprogram/matrix.c

#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

void print_matrix(const uint64_t row_length, const uint64_t column_length, const uint64_t matrix[row_length][column_length]) {
    for (uint64_t column_index=0; column_index < column_length; column_index++) {
        for (uint64_t row_index=0; row_index < row_length; row_index++) {
            printf("%lu ", matrix[row_index][column_index]);
        }
        puts("");
    }
}

int gemm_basic(const uint64_t row_length1, const uint64_t column_length1, const uint64_t matrix1[row_length1][column_length1],
                          const uint64_t row_length2, const uint64_t column_length2, const uint64_t matrix2[row_length2][column_length2],
                          uint64_t output_matrix[row_length1][column_length2]) {
    if (row_length1 != column_length2) {
        return 1;
    }

    uint64_t sum;

    for (uint64_t i = 0; i < row_length1; i++) {
        for (uint64_t j = 0; j < column_length2; j++) {
            sum = 0;

            for (uint64_t k = 0; k < row_length1; k++) {
                sum += matrix1[i][k] * matrix2[k][j];
            }

            output_matrix[i][j] = sum;
        }
    }

    return 0;
}

int read_csv(const char *file_name, const uint64_t row_length, const uint64_t column_length, uint64_t output_matrix[row_length][column_length]) {
    FILE *file_ptr;
    uint64_t bufsize = row_length*2+1; // have to account for delimiters
    char buffer[bufsize];
    char *value, *file_line;
    uint64_t row_index = 0, column_index = 0;

    file_ptr = fopen(file_name, "r");
    if (file_ptr == NULL) {
        puts("Unable to open csv");
        return 1;
    }

    while ((file_line = fgets(buffer, bufsize, file_ptr)) != NULL) {
        // This shit is just needed and I dont know why
        file_line[strcspn(file_line, "\n")] = 0;
        value = strtok(file_line, ";,");

        // for some reason there are two NULLs at the end of a line
        // and I dont wanna increment the column_index
        if (value == NULL) {
            continue;
        }

        while (value != NULL) {
            output_matrix[row_index++][column_index] = strtoul(value, NULL, 0);
            value = strtok(NULL, ";,");
        }

        row_index = 0;
        column_index++;
    }

    fclose(file_ptr);

    return 0;
}