Compilare: user.cpp: In function ‘int main()’: user.cpp:47:8: warning: unused variable ‘j’ [-Wunused-variable] int i,j,l1,c1,l,c,m; ^ user.cpp:48:30: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("alee.in","r",stdin); ^ user.cpp:49:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("alee.out","w",stdout); ^ user.cpp:50:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&m); ^ user.cpp:53:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&l,&c); ^ user.cpp:56:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d",&l,&c,&l1,&c1); ^