Compilare: user.cpp: In function ‘int main()’: user.cpp:12:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<=strlen(s);i++) ^ user.cpp:14:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<=strlen(s);i++) ^ user.cpp:15:19: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if((s[i]>='A')&&(s[i]<='Z')||(s[i]>='a')&&(s[i]<='z'))k2++; ^