Compilare: user.cpp: In function ‘int main()’: user.cpp:46:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("subarbore.in", "r", stdin); ^ user.cpp:47:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("subarbore.out", "w", stdout); ^ user.cpp:48:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d", &n, &m); ^ user.cpp:50:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] {scanf ("%d%d%d", &x, &y, &c); a[x][y]=c; a[y][x]=c;} ^ user.cpp:56:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &T); ^ user.cpp:58:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] {scanf ("%d", &t[i]); st[++VV]=t[i]; ap[t[i]]=1;} ^ user.cpp: In function ‘void back(int)’: user.cpp:25:35: warning: ‘I’ may be used uninitialized in this function [-Wmaybe-uninitialized] COST+=minim; luat[st[I]]=1; ^