LeetCode 891. Sum of Subsequence Widths

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class Solution {
    static int N = 100010, MOD = (int) 1e9 + 7;
    static long[] p = new long[N];
    static {
        p[0] = 1;
        for (int i = 1; i < N; ++i) p[i] = p[i - 1] * 2 % MOD;
    }
    public int sumSubseqWidths(int[] nums) {
        int n = nums.length;
        long ans = 0;
        Arrays.sort(nums);
        for (int i = 0; i < n; ++i) {
            ans += (p[i] * nums[i]) % MOD;
            ans %= MOD;
            ans -= (p[n - i - 1] * nums[i]) % MOD;
            ans %= MOD;
        }
        return (int) ans;
    }
}
// https://leetcode.cn/problems/sum-of-subsequence-widths/solutions/1977822/by-ac_oier-6tyk/