#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX_LINE_LENGTH 1000

// 分配矩陣記憶體
int** allocateMatrix(int rows, int cols) {
	int i;
    int** matrix = (int**)malloc(rows * sizeof(int*));
    for (i = 0; i < rows; i++) {
        matrix[i] = (int*)malloc(cols * sizeof(int));
    }
    return matrix;
}

// 釋放矩陣記憶體
void freeMatrix(int** matrix, int rows) {
	int i ;
    for (i = 0; i < rows; i++) {
        free(matrix[i]);
    }
    free(matrix);
}

// 矩陣乘法
void mul(int **a, int **b, int **c, int m, int k, int n) {
	int i , j , l ;
    for (i = 0; i < m; i++) {
        for (j = 0; j < n; j++) {
            c[i][j] = 0;
            for (l = 0; l < k; l++) {
                c[i][j] += a[i][l] * b[l][j];
            }
        }
    }
}

// 讀取矩陣並返回維度
int** readMatrix(FILE* file, int* rows, int* cols) {
    char line[MAX_LINE_LENGTH];
    int** matrix = NULL;
    *rows = 0;
    *cols = 0;

    while (fgets(line, sizeof(line), file)) {
        if (strlen(line) <= 1) break;  // 空行表示矩陣結束

        (*rows)++;
        int tempCols = 0;
        char* token = strtok(line, " \t\n");
        
        while (token != NULL) {
            tempCols++;
            token = strtok(NULL, " \t\n");
        }

        if (*cols == 0) {
            *cols = tempCols;
            matrix = allocateMatrix(*rows, *cols);
        }

        if (tempCols != *cols) {
            printf("錯誤：矩陣列數不一致\n");
            exit(1);
        }

        // 重新讀取該行並存儲數據
        int col = 0;
        token = strtok(line, " \t\n");
        while (token != NULL) {
            matrix[*rows - 1][col++] = atoi(token);
            token = strtok(NULL, " \t\n");
        }
    }

    return matrix;
}

int main() {
	int i , j ;
    FILE *file = fopen("matrix_input.txt", "r");
    if (file == NULL) {
        printf("無法開啟檔案\n");
        return 1;
    }

    int m, k1, k2, n;
    int **arr_a, **arr_b, **arr_c;

    // 讀取第一個矩陣
    arr_a = readMatrix(file, &m, &k1);

    // 讀取第二個矩陣
    arr_b = readMatrix(file, &k2, &n);

    fclose(file);

    // 檢查矩陣是否可以相乘
    if (k1 != k2) {
        printf("錯誤：這兩個矩陣無法相乘\n");
        freeMatrix(arr_a, m);
        freeMatrix(arr_b, k2);
        return 1;
    }

    // 分配結果矩陣的空間
    arr_c = allocateMatrix(m, n);

    // 執行矩陣乘法
    mul(arr_a, arr_b, arr_c, m, k1, n);

    // 輸出結果
    printf("矩陣乘法結果：\n");
    for (i = 0; i < m; i++) {
        for (j = 0; j < n; j++) {
            printf("%d ", arr_c[i][j]);
        }
        printf("\n");
    }

    // 釋放記憶體
    freeMatrix(arr_a, m);
    freeMatrix(arr_b, k1);
    freeMatrix(arr_c, m);

    return 0;
}