Compilare: user.cpp: In function ‘void PrefixFunction(const string&, std::vector<int>&)’: user.cpp:9:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 1; i < prefix.size(); i++) { ^ user.cpp: In function ‘void KMP(const string&, const string&)’: user.cpp:36:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i < str.size()) { ^ user.cpp:37:50: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(str[i] == word[j] && j < word.size() && i < str.size()){ ^ user.cpp:37:68: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(str[i] == word[j] && j < word.size() && i < str.size()){ ^ user.cpp:41:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(j == word.size()){ ^