Compilare: main.cpp: In function 'int main()': main.cpp:13:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (p<=s.size() && s.size()<=100) { ~^~~~~~~~~~ main.cpp:15:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (p<s.size()) i=s[p]; ~^~~~~~~~~ main.cpp:16:15: warning: statement has no effect [-Wunused-value] for (i; i<='z'; ++i) { ^