Compilare: main.cpp: In function 'int main()': main.cpp:56:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = a.length(); i < b.length(); ++i) { ~~^~~~~~~~~~~~ main.cpp:36:40: warning: 'h2b.rollingHash::maxpower' may be used uninitialized in this function [-Wmaybe-uninitialized] this->val = ((this->val - (out * this->maxpower) % this->n + this->n) * this->key + in) % this->n; ~~~~~^~~~~~~~~~~~~~~~~ main.cpp:51:22: note: 'h2b.rollingHash::maxpower' was declared here rollingHash h1b, h2b; ^~~ main.cpp:36:40: warning: 'h1b.rollingHash::maxpower' may be used uninitialized in this function [-Wmaybe-uninitialized] this->val = ((this->val - (out * this->maxpower) % this->n + this->n) * this->key + in) % this->n; ~~~~~^~~~~~~~~~~~~~~~~ main.cpp:51:17: note: 'h1b.rollingHash::maxpower' was declared here rollingHash h1b, h2b; ^~~