Compilare: main.cpp: In function 'int main()': main.cpp:21:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<s.size(); i++) { ~^~~~~~~~~ main.cpp:58:8: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses] if(s[i - 1] != 'x') ^