Compilare: user.c: In function ‘main’: user.c:18:5: warning: implicit declaration of function ‘abs’ [-Wimplicit-function-declaration] if(abs(Sx-Fx)+abs(Sy-Fy)==S){ ^ user.c:12:7: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%lld %lld %lld %lld", &Sx, &Sy, &S, &N); ^ user.c:15:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%lld", &Fx); ^ user.c:16:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%lld", &Fy); ^