Compilare: main.c: In function 'main': main.c:24:20: warning: implicit declaration of function 'rand' [-Wimplicit-function-declaration] fprintf(out,"%d",rand() % 2); ^~~~ main.c:16:2: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d",&n); ^~~~~~~~~~~~~~~~~~