Compilare: user.cpp: In function ‘int main()’: user.cpp:38:15: warning: unused variable ‘c’ [-Wunused-variable] int n, m, c = 0; ^ user.cpp:39:32: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (in, "%d%d", &n, &m); ^ user.cpp:43:36: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (in, "%d%d", &x, &y); ^ user.cpp:54:15: warning: ‘start’ may be used uninitialized in this function [-Wmaybe-uninitialized] bfs(start); ^