Compilare: main.cpp: In function 'void solve()': main.cpp:83:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<positive.size(); ++i) ~^~~~~~~~~~~~~~~~ main.cpp:92:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i+1<sol.size(); ++i) ~~~^~~~~~~~~~~ main.cpp:110:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<sol.size(); ++i) ~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:131:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("tester.in", "r", stdin); ^ main.cpp:132:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("tester.out", "w", stdout); ^