Compilare: user.cpp: In function ‘void preKmp(std::string, int*)’: user.cpp:17:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<x.length()) ^ user.cpp: In function ‘void KMP(std::string)’: user.cpp:35:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j<s.length()) ^ user.cpp:40:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i>=k.length()) ^ user.cpp: In function ‘int main()’: user.cpp:69:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<=s.length()+1;++i) ^ user.cpp:50:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("carte.in","r",stdin); ^ user.cpp:51:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("carte.out","w",stdout); ^