题意：
给出一个数列a[]a[]a[],以及一个模数mmm，计算∏1<=i<j<=n∣a[i]−a[j]∣\prod_{1 <= i < j <= n} \left|a[i] – a[j]\right|∏1<=i<j<=n∣a[i]−a[j]∣.
数据范围：1<=n<=2∗105,1<=m<=1000,0<=a[i]<=1091 <= n <= 2 * 10 ^ 5, 1 <= m <= 1000, 0 <= a[i] <= 10^91<=n<=2∗105,1<=m<=1000,0<=a[i]<=109.
思路：
很容易想到的是O(n2)O(n^2)O(n2)的做法，但是看到nnn的范围，明
