Compilare: user.c: In function ‘Insert’: user.c:25:9: warning: implicit declaration of function ‘tolower’ [-Wimplicit-function-declaration] index = tolower(word[i]) - 'a'; ^ user.c: In function ‘Delete’: user.c:92:56: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if(ptr -> occurences > 1 || ptr -> occurences == 1 && vertices){ ^ user.c: In function ‘main’: user.c:134:5: warning: implicit declaration of function ‘isdigit’ [-Wimplicit-function-declaration] if(isdigit(ch)){ ^ user.c:127:8: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("trie.in", "r", stdin); ^ user.c:128:8: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("trie.out", "w", stdout); ^ user.c:137:14: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &task); ^ user.c:139:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s", word); ^ user.c: In function ‘Delete’: user.c:80:31: warning: ‘j’ may be used uninitialized in this function [-Wmaybe-uninitialized] }if(vertices > 1 && i > j){ ^ user.c: In function ‘main’: user.c:134:15: warning: ‘ch’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(isdigit(ch)){ ^