Compilare: main.cpp: In member function 'void KMP::build(const string&)': main.cpp:34:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1, len = 0; i < pattern.size(); p[i] = len, i++) ~~^~~~~~~~~~~~~~~~ main.cpp: In constructor 'KMP::KMP(const string&)': main.cpp:29:16: warning: 'KMP::p' will be initialized after [-Wreorder] vector<int> p; ^ main.cpp:28:17: warning: 'const string KMP::pattern' [-Wreorder] const string pattern; ^~~~~~~ main.cpp:42:4: warning: when initialized here [-Wreorder] KMP(const string& pattern) : p(pattern.size()), pattern(pattern) ^~~ main.cpp: In member function 'std::vector<int> KMP::run(const string&) const': main.cpp:50:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0, j = 0; i < text.size(); i++) ~~^~~~~~~~~~~~~ main.cpp:54:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (j == pattern.size()) idxs.push_back(i - j + 1), j = p[j - 1]; ~~^~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:64:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("strmatch.in", "r", stdin); ^ main.cpp:65:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("strmatch.out", "w", stdout); ^