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

int main()
{
	double wyraz1;
	double wyraz2;
	double tab[10]={12.0,15.0,17.0,21.0,15.5,16.25,17.11,19.22,22.22,99.97};
	double tab2[10];
	int odstep=sizeof(tab[0]);
	printf("%d \n",odstep);
	int i=0;
	FILE *p;
	p=fopen("DANE.BIN","w");
	if(p==NULL)
		printf("Pliczek sie nie otworzyl");
	else
	{
		for(i=0;i<20;i++)
		{
			fwrite(tab,sizeof(tab),1,p);
		}

	}
	fclose(p);
	p=fopen("DANE.BIN","ab+");
	while(!feof(p))
	{
		fread(tab2,sizeof(tab2),1,p);
	}
	fclose(p);
	for(i=0;i<10;i++)
		printf("%.2f ",tab2[i]);
	p=fopen("DANE.BIN","a+b");
		fseek(p,0,SEEK_SET);
		fread(&wyraz1,sizeof(double),1,p);
		printf("%.2f",wyraz1);
		fseek(p,-odstep,SEEK_END);
		fread(&wyraz2,sizeof(double),1,p);
		printf("%.2f",wyraz2);
		fseek(p,0,SEEK_SET);
		fwrite(&wyraz2,sizeof(double),1,p);
		fseek(p,-odstep,SEEK_END);
		fwrite(&wyraz1,sizeof(double),1,p);
		fclose(p);
		printf("\n------------------------------------------------------\n");
		p=fopen("DANE.BIN","r");
		while(!feof(p))
	{
		fread(tab2,sizeof(tab2),1,p);
	}
	fclose(p);
		for(i=0;i<10;i++)
		printf("%.2f ",tab2[i]);
	return 0;
}