Compilare: user.cpp: In function ‘int main()’: user.cpp:78:47: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<act->where.size();++i) ^ user.cpp:49:36: 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:50:38: 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:54:42: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %s\n", &N, &numWords, S); ^ user.cpp:59:48: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n%s\n", &currentlength, that); ^