Compilare: main.cpp: In function 'int main()': main.cpp:17:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<s.size()-1;i++) ~^~~~~~~~~~~ main.cpp:23:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while( i<s.size() and s[i-1]>s[i] and s[i]<s[i+1] ) ~^~~~~~~~~ main.cpp:35:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();i++) ~^~~~~~~~~