Compilare: user.cpp:4:6: warning: ISO C++ forbids declaration of ‘main’ with no type [-Wreturn-type] main() { freopen("split.in", "r", stdin); int N, Max = -100000001, Min = 100000001; scanf("%d", &N); for(int i = 1; i <= N; ++ i) { scanf("%d", &v[i]); Max = std :: max(v[i], Max); ^ user.cpp: In function ‘int main()’: user.cpp:4:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] main() { freopen("split.in", "r", stdin); int N, Max = -100000001, Min = 100000001; scanf("%d", &N); for(int i = 1; i <= N; ++ i) { scanf("%d", &v[i]); Max = std :: max(v[i], Max); ^ user.cpp:4:100: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] main() { freopen("split.in", "r", stdin); int N, Max = -100000001, Min = 100000001; scanf("%d", &N); for(int i = 1; i <= N; ++ i) { scanf("%d", &v[i]); Max = std :: max(v[i], Max); ^ user.cpp:4:151: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] main() { freopen("split.in", "r", stdin); int N, Max = -100000001, Min = 100000001; scanf("%d", &N); for(int i = 1; i <= N; ++ i) { scanf("%d", &v[i]); Max = std :: max(v[i], Max); ^