Score : $400$ points
We have $N$ integers. The $i$-th integer is $A_i$.
Find $\sum_{i=1}^{N-1}\sum_{j=i+1}^{N} (A_i \mbox{ XOR } A_j)$, modulo $(10^9+7)$.
The XOR of integers $A$ and $B$, $A \mbox{ XOR } B$, is defined as follows:
Input is given from Standard Input in the following format:
$N$ $A_1$ $A_2$ $...$ $A_N$
Print the value $\sum_{i=1}^{N-1}\sum_{j=i+1}^{N} (A_i \mbox{ XOR } A_j)$, modulo $(10^9+7)$.
3 1 2 3
6
We have $(1\mbox{ XOR } 2)+(1\mbox{ XOR } 3)+(2\mbox{ XOR } 3)=3+2+1=6$.
10 3 1 4 1 5 9 2 6 5 3
237
10 3 14 159 2653 58979 323846 2643383 27950288 419716939 9375105820
103715602
Print the sum modulo $(10^9+7)$.