Compilare: main.cpp: In function 'int main()': main.cpp:13:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<s.size(); i++) ~^~~~~~~~~ main.cpp:19:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=1;j<=s.size()-i-1;j++) ~^~~~~~~~~~~~~~ main.cpp:9:20: warning: unused variable 'y' [-Wunused-variable] int b,r,nr=0,x,y=1; ^