Compilare: main.cpp: In function 'void prec()': main.cpp:17:14: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::deque<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 17 | for(i=2;i<s.size();i++){ | ~^~~~~~~~~ main.cpp:15:11: warning: unused variable 'j' [-Wunused-variable] 15 | int i,j; | ^ main.cpp: In function 'int main()': main.cpp:37:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::deque<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 37 | for(j=1;j<s.size();j++) | ~^~~~~~~~~ main.cpp:41:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::deque<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 41 | for(j=1;j<s.size();j++){ | ~^~~~~~~~~