Compilare: user.cpp: In function ‘bool parallel_bfs(int, int)’: user.cpp:69:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (edg_ptr[ta] < g[ta].size() && f[g[ta][edg_ptr[ta]]] == fptr) ~~~~~~~~~~~~^~~~~~~~~~~~~~ user.cpp:71:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (edg_ptr[ta] == g[ta].size()) { ~~~~~~~~~~~~^~~~~~~~~~~~~~~ user.cpp:75:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (edg_ptr[tb] < g[tb].size() && f[g[tb][edg_ptr[tb]]] == fptr) ~~~~~~~~~~~~^~~~~~~~~~~~~~ user.cpp:77:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (edg_ptr[tb] == g[tb].size()) { ~~~~~~~~~~~~^~~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:141:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("nespus.in", "r", stdin); ^ user.cpp:142:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("nespus.out", "w", stdout); ^ user.cpp: In function ‘char next_ch()’: user.cpp:33:30: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, BMAX, stdin); ^