Compilare: main.cpp: In function 'bool check(int)': main.cpp:30:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < v.size(); ++i) ~~^~~~~~~~~~ main.cpp:33:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 2; i < v.size(); ++i) ~~^~~~~~~~~~ main.cpp:44:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 2; i < v.size(); ++i) ~~^~~~~~~~~~ main.cpp:48:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < sol.size(); ++j) ~~^~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:84:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 2; i < n; ++i) ~~^~~ main.cpp:85:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (check(i) && sol.size() == n) ~~~~~~~~~~~^~~~