Compilare: main.cpp: In function 'int check(int)': main.cpp:27:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 27 | for( j = len; j < s[i].size(); j++ ) { | ~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:41:10: warning: unused variable 'j' [-Wunused-variable] 41 | int i, j, ans, k; | ^ main.cpp:41:18: warning: unused variable 'k' [-Wunused-variable] 41 | int i, j, ans, k; | ^