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:70:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<s.length();++i) ^ user.cpp:66:7: warning: unused variable ‘cnt’ [-Wunused-variable] int cnt=0; ^ user.cpp:67:8: warning: unused variable ‘word’ [-Wunused-variable] bool word=false; ^ user.cpp:68:7: warning: unused variable ‘j’ [-Wunused-variable] int j=vis[0]; ^ 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); ^