Compilare: main.cpp: In function 'int main()': main.cpp:67:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("trie.in", "r", stdin); ^ main.cpp:68:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("trie.out", "w", stdout); ^ main.cpp:69:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &op); ^ main.cpp:71:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%s", s + 1); ^ main.cpp:87:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &op); ^