Compilare: user.cpp: In function ‘int main()’: user.cpp:11:13: warning: unused variable ‘j’ [-Wunused-variable] int r=0,j=1; ^ user.cpp:7:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dreptunghi.in","r",stdin); ^ user.cpp:8:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dreptunghi.out","w",stdout); ^ user.cpp:10:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&m); ^