Compilare: main.cpp: In function 'void Lps()': main.cpp:20:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int i = 0; i < s.size(); ++i ) ~~^~~~~~~~~~ main.cpp:22:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int i = 1; i < s.size(); ++i ) ~~^~~~~~~~~~ main.cpp:35:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int i = 1; i < s.size(); ++i ) ~~^~~~~~~~~~