Compilare: main.cpp: In function 'void bfs(int)': main.cpp:22:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0 ; j < G[u].size() ; j ++) ~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:38:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sate.in" , "r" , stdin); ^ main.cpp:39:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sate.out" , "w" , stdout); ^ main.cpp:41:53: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d\n" , &n , &m , &start , &finish); ^