Compilare: main.cpp: In function 'int main()': main.cpp:85:18: warning: converting to non-pointer type 'char' from NULL [-Wconversion-null] cuv[l - 1] = NULL; ^~~~ main.cpp:88:7: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses] if(!feof(stdin)) ^ main.cpp:79:8: warning: unused variable 'c' [-Wunused-variable] char c; ^ main.cpp:77:33: 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:78:35: 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:82:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d ", &op); ^ main.cpp:83:26: warning: ignoring return value of 'char* fgets(char*, int, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fgets(cuv, 22, stdin); ^