從兩個文本文件乘以兩個矩陣給出輸出爲零

Question

我想從兩個文本文件中讀取矩陣，將它存儲到2個數組中，然後嘗試將這兩個矩陣相乘並將結果存儲在數組中。 乘法結果即將000.

下面是我的代碼

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

int main(int argc,char *argv[]) 
{ 
    FILE *fr1, *fr2, *fw; 
    char *line = malloc(1000); 
    int count = 0; 
    //To read a file use the fopen() function to open it 
    fr1 = fopen(argv[1], "r"); 
    //If the file fails to open the fopen() returns a NULL 
    if (fr1 == NULL) { 
     printf("Cannot open %s. Program terminated...",argv[1]); 
     exit(1); 
    } 

    // Similar to the above method read the second file 
    fr2 = fopen(argv[2], "r"); 
    if (fr2 == NULL) { 
     printf("Cannot open %s. Program terminated...",argv[2]); 
     exit(1); 
    } 

    double *data = (double*) malloc(1000*sizeof(double)); 
    if(data == NULL) 
    { 
     printf("Error in allocating memory"); 
     return EXIT_FAILURE; 
    } 
    // Read number of columns and number of rows of first matrix 
    getline(&line, &count, fr1); 
    int read = -1, cur = 0, columCount1 = 0; 
    while(sscanf(line+cur, "%lf%n", &data[columCount1], &read) == 1) 
    {cur+=read; columCount1++;} 

    int rowCount1 = 1; 
    while(getline(&line, &count, fr1) != -1) {rowCount1++;} 
    printf("%d\n",columCount1); 
    printf("%d\n",rowCount1); 

    // Read number of columns and number of rows of second matrix 
    getline(&line, &count, fr2); 
    read = -1,cur = 0; 
    int columCount2 = 0; 
    while(sscanf(line+cur, "%lf%n", &data[columCount2], &read) == 1) 
    {cur+=read; columCount2++;} 

    int rowCount2 = 1; 
    while(getline(&line, &count, fr2) != -1) {rowCount2++;} 
    printf("%d\n",columCount2); 
    printf("%d\n",rowCount2); 
    int i=0; 
    int j=0; 

    int **mat1 = (int **)malloc(rowCount1 * sizeof(int*)); 
    for(i = 0; i < rowCount1; i++) 
    mat1[i] = (int *)malloc(columCount1 * sizeof(int)); 

    fseek(fr1, 0, SEEK_SET); 

    for(i=0; i<rowCount1; i++) 
    { 
     for(j=0; j<columCount1; j++) 
      fscanf(fr1,"%d",&mat1[i][j]); 
    } 

    i = 0; 
    j = 0; 

    printf("\n\n"); 
    //print matrix 1 
    for(i=0; i<rowCount1; i++) 
    { 
     for(j=0; j<columCount1; j++) 
      printf("%d",mat1[i][j]); 

     printf("\n"); 
    } 

    i = 0; 
    j = 0; 
    int **mat2 = (int **)malloc(rowCount2 * sizeof(int*)); 
    for(i = 0; i < rowCount2; i++) 
     mat2[i] = (int *)malloc(columCount2 * sizeof(int)); 

    fseek(fr2, 0, SEEK_SET); 

    for(i=0; i<rowCount2; i++) 
    { 
     for(j=0; j<columCount2; j++) 
      fscanf(fr2,"%d",&mat2[i][j]); 
    } 

    i = 0; 
    j = 0; 

    printf("\n\n"); 
    //print matrix 2 
    for(i=0; i<rowCount2; i++) 
    { 
     for(j=0; j<columCount2; j++) 
      printf("%d",mat2[i][j]); 

     printf("\n"); 
    } 

    i = 0; 

    int **mat3 = (int **)malloc(rowCount1 * sizeof(int*)); 
    for(i = 0; i < rowCount1; i++) 
     mat3[i] = (int *)malloc(columCount2 * sizeof(int)); 
    i = 0; 
    j = 0; 
    int k = 0; 
    int sum = 0; 
    //multiplication of two matrices 
    for(i=0; i<rowCount1; i++) 
    { 
     for(j=0; j<columCount2; j++) 
     { 
      sum=0; 
      for(k=0; k<rowCount2; k++) 
       sum+=mat1[i][k]*mat2[k][j]; 
     } 
     mat3[i][j] = sum; 
    } 

    i = 0; 
    j = 0; 


    //print multiplication result 
    printf("\n\nResult = \n\n"); 

    for(i=0; i<rowCount1; i++) 
    { 
     for(j=0; j<columCount2; j++) 
      printf("%d",mat3[i][j]); 

     printf("\n"); 
    } 

    return 0; 
} 

Answer 1

1）矩陣乘法之前檢查如果矩陣1中的列數是相同的行中的矩陣編號爲2

//Check if number of col in mat1 is same as number of rows in mat2 
if(columCount1 != rowCount2) 
{ 
    puts("The number of columns in Matrix 1 is not same as the number of rows in Matrix 2"); 
    exit(1); 
} 

2）代碼的兩個矩陣的乘法：

for(i=0;i<rowCount1;i++) 
{ 
    for(j=0;j<columCount2;j++) 
    { 
     mat3[i][j]=0; 
     for(k=0;k<columCount1;k++) 
     { 
      mat3[i][j] = mat3[i][j]+mat1[i][k] * mat2[k][j]; 
     } 
    } 
} 

3）main()

/* After printing the results free the memory */ 
for(i=0; i< rowCount1; i++) 
    free(mat1[i]); 
free(mat1); 

for(i=0; i< rowCount2; i++) 
    free(mat2[i]); 
free(mat2); 

for(i=0; i< rowCount1; i++) 
    free(mat3[i]); 
free(mat3); 

free(data);