Storing numbers as (x, y) cordinates from a file at a specific point

问题

I have an Instance File from which I need to store the NUM_PT and all the respective co-ordinates in the form of a 2D array system (personal choice so I can access them easily). I am able to retrieve the NUM_PT but I am stuck at reading the successive cordinates into my array.

HERE IS WHAT I HAVE DONE

/* Assignment 2 */

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



#define MAXS 256

int main(int argc, char *argv[])

{

  int num_pt;
  int inputfile = 0, outputfile = 0, i;

  for (i = 1; i < argc; i++)
    {
      if (strcmp (argv[i], "-i") == 0)
          inputfile = i+1;
      if (strcmp (argv[i], "-o") == 0)
          outputfile = i+1;
    }
  if (inputfile == 0)
    {
      /* invalid command line options */
      printf("\nIncorrect command-line...\n");
      printf("> %s [-i inputfile [-o outputfile]]\n\n", argv[0]);
      exit(0);
    }

  FILE *fp;
  fp = fopen(argv[inputfile], "r");

  int count = 0;      
  if (fp == 0)
    {
      printf("\nCould not find %s\n", argv[inputfile]);
      exit(0);
    }

  char line[MAXS];
  while (fgets(line, sizeof line, fp) != NULL)
    {
      if (count == 4)
        {
         fscanf(fp, "%d", &num_pt);
         break;
        }
      else
        count++;

    }

  int arr[num_pt][1];
  while (fgets(line, sizeof line, fp) != NULL)
    {
      if (count == 5)
        {
          int k, j, cord;
          for (k = 0; k < num_pt; k++)
             {
              for (j = 0; j < num_pt; j++)
                 {
                   while (fscanf(fp, "%d%d", &cord) > 0)
                        {
                         arr[k][j] = cord;
                         j++;
                        }
                 }
              }
        }
    }
  fclose(fp)
  return 0;

}

After retrieving NUM_PT i tried reinitializing the count to 5 because the cordinates start from **LINE 6* in the file.

ERROR FROM COMPILER

Language: c99 ; Compiler: gcc

回答1:

sample for "Storing numbers as (x, y) cordinates from a file" (It is better not to fix the reading position)

#include <stdio.h>

typedef struct point {
    int x, y;
} Point;

int readPoint(FILE *fp, Point *p);
int readInt(FILE *fp, int *n);

int main(void){
    FILE *fp = fopen("instance10_001.txt", "r");
    Point p;
    int MAX_X, MAX_Y;

    readPoint(fp, &p);
    MAX_X = p.x;
    MAX_Y = p.y;
    printf("MAX_X:%d, MAX_Y:%d\n", MAX_X, MAX_Y);

    int NUM_PT;
    readInt(fp, &NUM_PT);
    printf("NUM_PT:%d\n", NUM_PT);

    Point arr[NUM_PT];
    for(int i = 0; i < NUM_PT; ++i){
        readPoint(fp, &arr[i]);
        printf("Point(%d, %d)\n", arr[i].x, arr[i].y);
    }
    fclose(fp);
}

int readLine(FILE *fp, char *buff, int buff_size){
    while(fgets(buff, buff_size, fp)){
        if(*buff == '#' || *buff == '\n')
            continue;
        return 1;
    }
    return 0;
}

#define LINE_MAX 128
int readPoint(FILE *fp, Point *p){
    char buff[LINE_MAX];
    if(readLine(fp, buff, sizeof buff)){
        return 2 == sscanf(buff, "%d %d", &p->x, &p->y);
    }
    return 0;
}
int readInt(FILE *fp, int *n){
    char buff[LINE_MAX];
    if(readLine(fp, buff, sizeof buff)){
        return 1 == sscanf(buff, "%d", n);
    }
    return 0;
}

来源：https://stackoverflow.com/questions/40538064/storing-numbers-as-x-y-cordinates-from-a-file-at-a-specific-point