Compilare: main.cpp: In function 'void solve2()': main.cpp:38:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < s.size() - 1; i++) ~~^~~~~~~~~~~~~~ main.cpp:47:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = poz + 2; i < s.size(); i++) ~~^~~~~~~~~~ main.cpp:54:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < s.size() - 1; i++) ~~^~~~~~~~~~~~~~ main.cpp:61:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = poz + 1; i + 1 < s.size(); i += 2) ~~~~~~^~~~~~~~~~ main.cpp:63:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i == s.size() - 1) ~~^~~~~~~~~~~~~~~