Compilare: main.cpp: In function 'int main()': main.cpp:15:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 1 ; i < tot.size() && sol.size() < 1000 ; ++ i) { ~~^~~~~~~~~~~~ main.cpp:22:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pi[i] == A.size()) {