Compilare: main.cpp: In function 'int main()': main.cpp:113:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < nodes.size(); i++) ~~^~~~~~~~~~~~~~ main.cpp:66:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("palatulvoltaic.in", "r", stdin); ^ main.cpp:68:44: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("palatulvoltaic.out", "w", stdout); ^