Compilare: user.cpp: In function ‘void Insert(Node*, int*)’: user.cpp:77:18: warning: NULL used in arithmetic [-Wpointer-arith] if (*word == NULL) ^ user.cpp: In function ‘void Delete(Node*, int*)’: user.cpp:91:18: warning: NULL used in arithmetic [-Wpointer-arith] if (*word == NULL) ^ user.cpp: In function ‘int Solve(Node*, int*, int*)’: user.cpp:105:18: warning: NULL used in arithmetic [-Wpointer-arith] if (*word == NULL) ^ user.cpp:127:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:131:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &N); ^ user.cpp:137:20: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(S); ^ /tmp/ccam9una.o: In function `main': user.cpp:(.text.startup+0x66): warning: the `gets' function is dangerous and should not be used.