如何计算出(非挖矿)下一难度值？

next_difficulty

/// The difficulty is defined as the maximum target divided by the block hash.
#[derive(Debug, Clone, Copy, PartialEq, PartialOrd, Eq, Ord)]
pub struct Difficulty {
    num: u64,
}

难度调整

difficulty = (diff_sum / DIFFICULTY_ADJUST_WINDOW) * BLOCK_TIME_WINDOW / adj_ts

相关概念：证明 Proof