Compilare: main.cpp: In function 'int main()': main.cpp:40:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=len_t; i<s.size(); ++i) { ~^~~~~~~~~ main.cpp:47:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<sol.size() && i<1000; ++i) ~^~~~~~~~~~~