Compilare: main.cpp: In function 'int validLen(int)': main.cpp:60:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 60 | for (int i = len; i <= str.size(); i++) { | ~~^~~~~~~~~~~~~ main.cpp: In instantiation of 'uint64_t logexp(uint64_t, uint64_t) [with long unsigned int MOD = 1000000007; uint64_t = long unsigned int]': main.cpp:35:48: required from 'roll_hash<B, MOD>::roll_hash(int, int) [with long unsigned int B = 127; long unsigned int MOD = 1000000007]' main.cpp:58:45: required from here main.cpp:13:22: warning: comparison of integer expressions of different signedness: 'int' and 'uint64_t' {aka 'long unsigned int'} [-Wsign-compare] 13 | for(int k = 1; k <= exp; k <<= 1) { | ~~^~~~~~