Compilare: user.cpp: In function ‘void Solve_dr()’: user.cpp:53:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,f,lx,ly,rx,ry; ^ user.cpp: In function ‘void Solve_st()’: user.cpp:80:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,f,lx,ly,rx,ry; ^ user.cpp: In function ‘void Read(int&)’: user.cpp:22:53: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(++poz==DIM) fread(buff,1,DIM,stdin),poz=0; ^ user.cpp:27:53: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(++poz==DIM) fread(buff,1,DIM,stdin),poz=0; ^ user.cpp: In function ‘int main()’: user.cpp:106:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("rays.in","r",stdin); ^ user.cpp:107:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("rays.out","w",stdout); ^ user.cpp:111:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&N); ^