来自 table 的背包问题数据存储在文件 C 中

Question

我正在尝试从包含 table 的文件中存储价值、重量和成本的数据，该文件包含价值、重量和成本的三列数字。 table 的长度可能会有所不同（9 或 21 行），具体取决于用户选择的文件。我在尝试存储此文件中的数据以用于强力函数来解决问题时遇到问题。这是我目前所拥有的。

     #include <stdio.h>
     #include <stdlib.h>
     #include <string.h>
     int main()
     {
         int nr_rows;
         int i = 1;
         int j = 2;
         int k = 3;
         int l,m,n = 0;
         int budget_cost;
         int weight_lim;
         char file_name[50];
         float c[nr_rows][3];
         char stringA[20] = "objectsA.txt";
         char stringB[20] = "objectsB.txt";

         printf("Enter the filename containing item listing: ");
         scanf("%s", &file_name);
         if(strcmp(file_name,stringA)==0)
         {
             nr_rows = 9;
         }
         else if(strcmp(file_name,stringB)==0)
         {
             nr_rows = 21;
         }
         printf("The number of rows is %d", nr_rows);
         float value[nr_rows], weight[nr_rows], price[nr_rows];
         FILE *fpointer;
         fpointer = fopen(file_name, "r");
         if(!fpointer)
         {
             printf("The file %s could not be opened.", file_name);
             return 1;
         }
         j=0;
         while(j<nr_rows)                            
         {                                          
             i=0;                      // Skip the first line
             while(i<3)
             {
                 fscanf(fpointer, "%f", &c[j][i]);
                 //printf("%.0f\n", c[j][i]);
                 if(i=1) /* Change this if statement so that 1 ,4 ,7 ,10
                            etc. activates*/
                 {
                     c[j][i] = v[l];
                     l++;
                     printf("%f", v[l]);
                 }
                 else if(i=2)/* Change this if statement so that 2,5,8 etc. 
                                activates*/
                 {
                     c[j][i] = w[m];
                     m++;
                 }    
                 else if(i=3)/* Change this if statement so that 3,6,9 etc. 
                                activates*/
                 {
                     c[j][i] = p[n];
                     n++;
                 }
                 i++;
             }
             j++;
         }
         fclose(fpointer);

Answer 1

//1. Read carefully your file name by doing:
scanf("%s", file_name); // instead of scanf("%s", &file_name);

//2. Declare  c[nr_rows][3] only after reading "nr_rows"

//3. The main "while" loop could look like this
while(j < nr_rows)
{
    fscanf(fpointer, "%f %f %f", &c[j][0], &c[j][1], &c[j][2]);
}
// Then,
fclose(fpointer);

来自 table 的背包问题数据存储在文件 C 中

knapsack problem data storage from table in a File C

c

computer-science

file

knapsack-problem

file-handling