Compilare: user.cpp: In function ‘int main()’: user.cpp:17:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<i;j++) ^ user.cpp:18:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i-j<=b&&i-j>=a&&(s[i]-s[j])%k==0) ^ user.cpp:18:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i-j<=b&&i-j>=a&&(s[i]-s[j])%k==0) ^