Compilare: main.cpp: In function 'int main()': main.cpp:28:28: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::set<int>::size_type {aka long unsigned int}' [-Wformat=] printf("%d\n", ord.size()); ^ main.cpp:14:7: warning: variable 'pos' set but not used [-Wunused-but-set-variable] int pos[2 + n]; ^~~ main.cpp:6:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("scmax.in", "r", stdin); ^ main.cpp:7:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("scmax.out", "w", stdout); ^ main.cpp:9:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:12:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i]); ^