Compilare: main.cpp: In function 'int main()': main.cpp:55:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < Gph[x].size(); i++){ ~~^~~~~~~~~~~~~~~ main.cpp: In function 'void Read(int&)': main.cpp:24:42: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(f, MAX, 1, IN), pos = 0; ^ main.cpp:29:42: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(f, MAX, 1, IN), pos = 0; ^ main.cpp: In function 'int main()': main.cpp:47:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("bfs.out", "w", stdout); ^