Compilare: user.cpp: In function ‘int main()’: user.cpp:30:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("distante.in" ,"r", stdin); ^ user.cpp:31:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("distante.out" ,"w", stdout); ^ user.cpp:34:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (scanf("%d", &Q); Q; --Q) ^ user.cpp:37:52: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d\n", &nodes , &edges, &root); ^ user.cpp:39:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &ans[i]); ^ user.cpp:43:47: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d\n", &x, &y, &cost); ^