Compilare: user.cpp: In function ‘int calc(int)’: user.cpp:42:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int calcn(int)’: user.cpp:82:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int calc2(int)’: user.cpp:123:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int calc2n(int)’: user.cpp:163:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:166:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cern.in","r",stdin); ^ user.cpp:167:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cern.out","w",stdout); ^ user.cpp:170:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%c",&p); ^ user.cpp:171:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&s,&t); ^