Compilare: user.cpp: In function ‘int main()’: user.cpp:78:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("lanterna.in", "rt", stdin); ^ user.cpp:79:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("lanterna.out", "wt", stdout); ^ user.cpp:81:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &k); ^ user.cpp:82:54: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i=1; i<=n; ++i) scanf("%d", &x), friends[i]=x; ^ user.cpp:84:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &m); ^ user.cpp:87:42: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &x, &y, &t, &w); ^ user.cpp: In function ‘bool bfs(int)’: user.cpp:60:25: warning: ‘j’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(j==n && times[nod][W]<time_nec) time_nec=times[nod][W]; ^ user.cpp: In function ‘int main()’: user.cpp:60:25: warning: ‘j’ may be used uninitialized in this function [-Wmaybe-uninitialized] user.cpp:32:12: note: ‘j’ was declared here int i, j, ww, tt, nod, p, W; ^