Compilare: user.cpp: In function ‘int main()’: user.cpp:69:11: warning: variable ‘kfgd’ set but not used [-Wunused-but-set-variable] FILE * kfgd = freopen("2sat.in","r",stdin); ^ user.cpp:72:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:76:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^