Compilare: In file included from /usr/include/c++/6/ext/pb_ds/detail/pat_trie_/pat_trie_.hpp:45:0, from /usr/include/c++/6/ext/pb_ds/detail/container_base_dispatch.hpp:90, from /usr/include/c++/6/ext/pb_ds/assoc_container.hpp:48, from main.cpp:2: main.cpp: In function 'int main()': main.cpp:228:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] assert(v.size() == 2*n*b); ~~~~~~~~~^~~~~~~~ main.cpp:10:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] #define FO(x) {freopen(#x".in","r",stdin);freopen(#x".out","w",stdout);} ^ main.cpp:147:9: note: in expansion of macro 'FO' FO(operatie); ^~ main.cpp:10:71: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] #define FO(x) {freopen(#x".in","r",stdin);freopen(#x".out","w",stdout);} ^ main.cpp:147:9: note: in expansion of macro 'FO' FO(operatie); ^~