Question

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

/*

Content of Text FILE

5        // no_of_process   
4        // no_of_resource_type
6 3 4 2  // vector E matrix
3 0 1 1  // 5x4 matrix
0 1 0 0
1 1 1 0
1 1 0 1
0 0 0 0 

*/


int main()
{
    FILE *file;
    int no_of_process;
    int no_of_resource_type;
    int *vector_E;
    int **C;
    int counter = 1, i, k;
    char unwanted[50];

    file = fopen("file_path\\file.txt", "r");
    if(file == NULL){
        printf("NO SUCH A FILE EXISTS!!!");
        exit(1);
    }


    while(!feof(file))
    {
        if(counter == 1){
            fscanf(file, "%d", &no_of_process);           // The number of process is set
            fscanf(file, "100[^\n]", unwanted);           // put in "unwanted" the un wanted chars untill you get \n 
            counter++;                                    // counter for selecting operation type
            printf("\nProcess: %d", no_of_process);
        }

        else if(counter == 2){
             fscanf(file, "%d", &no_of_resource_type);    // The number of resource type is set
             fscanf(file, "100[^\n]", unwanted);          // put in "unwanted" the un wanted chars untill you get \n 
             counter++;                                   // counter for selecting operation type                                
             printf("\nType: %d\n", no_of_resource_type);
        }

        else if(counter == 3){
             vector_E = (int *)malloc(sizeof(int)*no_of_resource_type);  // Allocating memory for vector_E of size # of resource type

             for(i=0; i<no_of_resource_type; i++){                        // fillling vector_E array 
                 fscanf(file, "%d", &vector_E[i]);
                 printf("%d ", vector_E[i]);
             }                        
             fscanf(file, "100[^\n]", unwanted);                         // put in "unwanted" the un wanted chars untill you get \n
             counter++;                                                  // counter for selecting operation type
             printf("\n");                                                  
        }

        else if(counter == 4){
             C = (int**)malloc(sizeof(int *)*no_of_process);             // Allocating memory for Current Allocation Matrix "part1"


             for(i=0; i<no_of_resource_type; i++)                       // Allocating memory for Current Allocation Matrix "part2"
                 C[i] = (int *)malloc(sizeof(int)*no_of_resource_type);


             for(i=0; i<no_of_process; i++){                             // Filling the Current Allocation Matrix
                 for(k=0; k<no_of_resource_type; k++){
                     fscanf(file, "%d", &C[i][k]);
                     printf("%d ", C[i][k]);
                 }
                 printf("\n");

                 // -------------------------------------------------------------------- ???????????
                // Problem is here !!!!!
                // --------------------------------------------------------------------- ???????????

                 fscanf(file, "100[^\n]", unwanted);                     // put in "unwanted" the un wanted chars untill you get \n

             }
        }
    }


    printf("# of Process: %d\n", no_of_process);
    printf("# of Resource Type: %d\n", no_of_resource_type);

    printf("Vector E\n");
    for(i=0; i<no_of_resource_type; i++)
        printf("%d ", vector_E[i]);

    printf("\nCurrent Allocation Matrix\n");
    for(i=0; i<no_of_process; i++){
        for(k=0; k<no_of_resource_type; k++){
            printf("%d ", C[i][k]);
        }
        printf("\n");
    }


    system("pause");
    return 0;
}

任务是从txt文件中读取数字。读取no_of_process，no_of_resource_type和vector_E矩阵没有问题。当程序读取“5x4矩阵”的第4行并且出现“程序中出现的访问冲突（分段错误）”错误时，会出现此问题。我将问题发生的地方标记为“问题就在这里!!!”。

有人可以解释这个问题的原因是什么以及如何解决它？

Answer 1

         C = (int**)malloc(sizeof(int *)*no_of_process); 
         for(i=0; i<no_of_resource_type; i++) 
             C[i] = (int *)malloc(sizeof(int)*no_of_resource_type);

好吧，你为int指针分配了“no_of_process”许多空格，但是在for循环中你只分配了“no_of_resource_type”行。所以将for循环更改为

         for(i=0; i<no_of_process; i++)

C编程错误：从.txt文件中读取

1 个答案: