Compilare: user.cpp: In function ‘void dfs(Trie*)’: user.cpp:63:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < t->v.size(); i++) { ^ user.cpp: In function ‘int main()’: user.cpp:70:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("virus.in", "r", stdin); ^ user.cpp:71:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("virus.out", "w", stdout); ^ user.cpp:73:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &l, &n); ^ user.cpp:74:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s", A); ^ user.cpp:76:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n%s", &k, s); ^