Compilare: main.cpp: In function 'int main()': main.cpp:25:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i < B.size()) { ~~^~~~~~~~~~ main.cpp:30:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = pow2; j >= 0 && i < B.size(); --j) { ~~^~~~~~~~~~ main.cpp:42:17: warning: ignoring return value of 'int system(const char*)', declared with attribute warn_unused_result [-Wunused-result] system("PAUSE"); ^