Compilare: main.c: In function 'main': main.c:16:23: warning: use of 'll' length modifier with 'f' type character has either no effect or undefined behavior [-Wformat=] fscanf ( fin, "%llf%llf%llf", &n, &x1, &y1 ); ^ main.c:16:27: warning: use of 'll' length modifier with 'f' type character has either no effect or undefined behavior [-Wformat=] fscanf ( fin, "%llf%llf%llf", &n, &x1, &y1 ); ^ main.c:16:31: warning: use of 'll' length modifier with 'f' type character has either no effect or undefined behavior [-Wformat=] fscanf ( fin, "%llf%llf%llf", &n, &x1, &y1 ); ^ main.c:19:27: warning: use of 'll' length modifier with 'f' type character has either no effect or undefined behavior [-Wformat=] fscanf ( fin, "%llf%llf", &x2, &y2 ); ^ main.c:19:31: warning: use of 'll' length modifier with 'f' type character has either no effect or undefined behavior [-Wformat=] fscanf ( fin, "%llf%llf", &x2, &y2 ); ^ main.c:24:26: warning: use of 'll' length modifier with 'f' type character has either no effect or undefined behavior [-Wformat=] fprintf( fout, "%.5llf", abs1(ans) ); ^ main.c:16:5: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf ( fin, "%llf%llf%llf", &n, &x1, &y1 ); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:19:9: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf ( fin, "%llf%llf", &x2, &y2 ); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~