Compilare: user.cpp: In function ‘int main()’: user.cpp:13:8: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(k<strlen(s)-3) ~^~~~~~~~~~~~ user.cpp:15:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<strlen(s)-k+1;i++){ok=1; ~^~~~~~~~~~~~~~ user.cpp:19:65: warning: self-comparison always evaluates to false [-Wtautological-compare] else {for(j=i;j<=i+k-1;j++)if(s[j]!=s[i+k-j+1]||s[(i+k+1)/2]!=s[(i+k+1)/2])ok=0; ~~~~~~~~~~~~^~~~~~~~~~~~~~