export default function sumSubseqWidths(nums: number[]): number {
    const MOD = 1000000007;
    nums.sort((a, b) => a - b);
    let res = 0;
    let x = nums[0],
        y = 2;
    for (let j = 1; j < nums.length; j++) {
        res = (res + nums[j] * (y - 1) - x) % MOD;
        x = (x * 2 + nums[j]) % MOD;
        y = (y * 2) % MOD;
    }
    return (res + MOD) % MOD;
}