第二题 思维题，将n个数存到k个桶里，如果选第i个桶，就不能选k-i个桶的 import java.util.Scanner; public class Main { static int[] a = new int[1005]; static long mod = 1000000007; static long pow[]=new long[100005]; public static void main(String[] args) { Scanner sc = new Scanner(System.in); int n = sc.nextInt(); int k = sc.nextInt(); pow[0]=1; for (int i = 1; i <=n; i++) { int x = sc.nextInt(); a[x % k]++; pow[i]=pow[i-1]*2%mod; } long ans=1; for (int i = 1; i < (k+1) / 2; i++) { ans*= (pow[a[i]] + pow[a[k - i]]-1); ans %= mod; } if(a[0]>0)ans*=2; if(k%2==0 &&a[k/2]>0)ans*=2; System.out.println(ans); } }