Compilare: main.cpp: In function 'int main()': main.cpp:14:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<sir.size();i++) ~^~~~~~~~~~~ main.cpp:20:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<ch.size();i++) ~^~~~~~~~~~ main.cpp:24:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<sir.size();j++) ~^~~~~~~~~~~ main.cpp:29:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int g=i;g<ch.size();g++)viz[ch[g].second]=false; ~^~~~~~~~~~