Compilare: user.cpp: In function ‘int bfs()’: user.cpp:48:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < G[node].size(); j++){ ^ user.cpp: In function ‘int main()’: user.cpp:83:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < G[D].size(); i++){ ^ user.cpp:113:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < V.size(); i++) ^ user.cpp: In function ‘char nextch()’: user.cpp:12:36: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf, BUF_SIZE, 1, fi); ^