Compilare: user.cpp: In function ‘int main()’: user.cpp:8:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,sol=1,x,n,m; ^ user.cpp:6:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pviz.in","r",stdin); ^ user.cpp:7:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pviz.out","w",stdout); ^ user.cpp:9:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:11:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^