Compilare: main.cpp: In function 'void solve()': main.cpp:28:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (first > v.size()) ~~~~~~^~~~~~~~~~ main.cpp:35:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (size_t i = 0; i < first; i++) ~~^~~~~~~ main.cpp: In function 'int main()': main.cpp:56:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (size_t i = 1; i <= n; i++) ~~^~~~