Compilare: main.cpp: In function 'int main()': main.cpp:18:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < s.size(); i++) ~~^~~~~~~~~~ main.cpp:22:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i < a.size(); i++) ~~^~~~~~~~~~ main.cpp:28:51: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(a[st] == a[dr] && st >= 0 && dr < a.size()) ~~~^~~~~~~~~~ main.cpp:44:51: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(a[st] == a[dr] && st >= 0 && dr < a.size()) ~~~^~~~~~~~~~