Tugas Sesi 15 No 2

#include <stdio.h>
int main(){
FILE *input;
FILE *output;
int a, b, i, selisih, hasil;
input = fopen("selisih.in", "r");
output = fopen("selisih.out", "w+");
printf("Selisih dari data pada file selisih.in = \n");
for(i = 0; i < 4; i++){
fscanf(input, "%i %i", &a, &b);
if (a > b){
selisih = a - b;
printf("%i\n", selisih);
}else{
selisih = b - a;
printf("%i\n", selisih);
}
fprintf(output, "%2i\n", selisih);
}
fclose(input);
fclose(output);
return 0;
}