Compilare: main.cpp: In function 'void precalc()': main.cpp:15:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 15 | for(int i = 1; i < a.size(); i) | ~~^~~~~~~~~~ main.cpp:15:34: warning: for increment expression has no effect [-Wunused-value] 15 | for(int i = 1; i < a.size(); i) | ^ main.cpp: In function 'int main()': main.cpp:60:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 60 | if(i == a.size()) | ~~^~~~~~~~~~~ main.cpp:65:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 65 | else if(j < b.size() && b[j] != a[i]) | ~~^~~~~~~~~~