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

int main()
{
    FILE *fp;
    fp = fopen("liczby2.dat", "a + b");
    fseek(fp, 0, SEEK_END);
    int liczbaEl = ftell(fp) / sizeof(int);
    printf("\nLiczba elementow: %d", liczbaEl);

    printf("\nElementy przed zamiana:");
    int buf, zam, zam1;
    fseek(fp, 0, 0);
    while(fread(&buf, sizeof(int),1,fp))
        printf("\n%d", buf);

    int el1, el2, k;
    printf("\nPodaj element pierwszy: ");
    scanf("%d", &el1);

    printf("\nPodaj element drugi: ");
    scanf("%d", &el2);


    fseek(fp, el1, 0);
    fread(&zam, sizeof(int), 1, fp);
    printf("\nzam = %d", zam);
    fseek(fp, el2, 0);
    fread(&zam1, sizeof(int), 1, fp);
    printf("\nzam1 = %d", zam1);
    fseek(fp, el2, 0);
    fwrite(&zam, sizeof(int), 1, fp);
    fseek(fp, el1, 0);
    fwrite(&zam1, sizeof(int), 1, fp);
    printf("\nElementy po zamianie");
    fseek(fp,0,0);
    while(fread(&buf, sizeof(int),1,fp))
        printf("\nElement: %d", buf);
    return 0;
}