Compilare: user.cpp: In function ‘void bfs()’: user.cpp:27:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v[a].size(); i++) ^ user.cpp: In function ‘void bfs2()’: user.cpp:46:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v[a].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:64:44: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d%d%d", &n, &m, &x, &y); ^ user.cpp:69:37: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d", &a, &b); ^