Compilare: user.cpp: In function ‘void failure(std::string)’: user.cpp:8:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = 0; i < p.size(); i++) f[i]=0; ^ user.cpp:10:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < p.size() && j < p.size()){ ^ user.cpp:10:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < p.size() && j < p.size()){ ^ user.cpp:26:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < p.size(); i++) ^ user.cpp: In function ‘void read()’: user.cpp:34:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&t); ^ user.cpp: In function ‘int main()’: user.cpp:42:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("prefixe.in","r",stdin); ^ user.cpp:43:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("prefixe.out","w",stdout); ^