Compilare: main.cpp: In function 'int main()': main.cpp:32:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<s.size(); i++) ~^~~~~~~~~ main.cpp:35:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=i; j<s.size(); j++) ~^~~~~~~~~ main.cpp:56:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<s.size(); i++) ~^~~~~~~~~ main.cpp:59:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=i; j<s.size(); j++) ~^~~~~~~~~