Compilare: user.cpp: In function ‘std::pair<int, int> calc(int)’: user.cpp:16:9: warning: unused variable ‘i’ [-Wunused-variable] int i,sp; ^ user.cpp: In function ‘int main()’: user.cpp:40:9: warning: unused variable ‘n’ [-Wunused-variable] int n,m,i,j,a,b; ^ user.cpp:40:11: warning: unused variable ‘m’ [-Wunused-variable] int n,m,i,j,a,b; ^ user.cpp:40:13: warning: unused variable ‘i’ [-Wunused-variable] int n,m,i,j,a,b; ^ user.cpp:40:15: warning: unused variable ‘j’ [-Wunused-variable] int n,m,i,j,a,b; ^ user.cpp:38:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("simpla.in","r",stdin); ^ user.cpp:39:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("simpla.out","w",stdout); ^ user.cpp:41:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a,&b); ^