Compilare: main.cpp: In function 'int main()': main.cpp:14:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<strlen(s);i++) ~^~~~~~~~~~ main.cpp:27:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<strlen(s);i++) ~^~~~~~~~~~