3_13_DOUBLEWEI 基本功练习のfile1_to_file2

#include<stdio.h>

 #include<stdlib.h>

 int main(void)

 {

  FILE *fd1;

  FILE *fd2;

  fd1=fopen("file1.txt","r");

  fd2=fopen("file2.txt","w");

  int *a=NULL;int *b=NULL;

  int max=10;

  a=(int *)malloc(max*sizeof(char));

  int i=0,j=0;

  while(fscanf(fd1,"%c",&a[i])!=EOF)

  {

   i++;

   j++;

    if(i>=max)

    {

     max=2*max;

     b=(int *)realloc(a,max*sizeof(int));

     a=b;

    }

   

  }

  for(;--j>=0;)

  {

   fprintf(fd2,"%c",a[j]);

  }

  fprintf(fd2,"\n");

  fclose(fd1);

  fclose(fd2);

  return 0;

 }