Compilare: user.cpp: In function ‘ll back(unsigned int)’: user.cpp:11:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0;i<L;i++) if(!B[i]){ ^ user.cpp:18:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(rs != -1 && (rs+C[i] < D[st] || D[st] == 0)) D[st] = rs+C[i]; ^ user.cpp: In function ‘int main()’: user.cpp:29:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0;i<N;i++){ ^ user.cpp:31:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0;j<L;j++){cin>>c; A[j]+=(c == '1' ? (1<<i) : 0);} ^ user.cpp:33:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0;j<L;j++) cin >> C[j]; ^