Compilare: main.cpp: In function 'int main()': main.cpp:20:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i < x.size(); ++i){ ~~^~~~~~~~~~ main.cpp:23:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(R < x.size() && x[R - i] == x[R]){ ~~^~~~~~~~~~ main.cpp:33:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(R < x.size() && x[R - i] == x[R]){ ~~^~~~~~~~~~ main.cpp:42:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = n; i < x.size(); ++i){ ~~^~~~~~~~~~