Compilare: main.cpp: In function 'int main()': main.cpp:42:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (topEntry.nextIdx != G[topEntry.node].size()) { ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~ main.cpp:19:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("dfs.in", "r", stdin); ^ main.cpp:20:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("dfs.out", "w", stdout); ^