Compilare: main.cpp: In function 'int main()': main.cpp:30:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<ec.length();i++) ~^~~~~~~~~~~~ main.cpp:65:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i+1<ec.size()) ~~~^~~~~~~~~~ main.cpp:65:19: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses] if(i+1<ec.size()) ^