Compilare: main.cpp: In function 'int main()': main.cpp:22:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<sir.size();i++) ~^~~~~~~~~~~ main.cpp:24:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i!=0 && i!=sir.size()-1) ~^~~~~~~~~~~~~~ main.cpp:35:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<sir.size();i++) ~^~~~~~~~~~~ main.cpp:52:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i==sir.size()-1) ~^~~~~~~~~~~~~~ main.cpp:19:10: warning: unused variable 'ok' [-Wunused-variable] bool ok=0; ^~