Leetcode 3578. Count Partitions With Max-Min Difference at Most K

• Leetcode 3578. Count Partitions With Max-Min Difference at Most K
  • 1. 解题思路
  • 2. 代码实现

• 题目链接：3578. Count Partitions With Max-Min Difference at Most K

1. 解题思路

这一题是一个动态规划的思路，不过我也是卡了一下，因为需要对动态规划的过程进行一下聚合，直接做会遇到超时的问题，后来是看了一下deepseek的解答搞定了，这里就不多说了，实在有点伤自尊……

2. 代码实现

给出python代码实现如下：

MOD = 10**9+7

class Solution:
    def countPartitions(self, nums: List[int], k: int) -> int:
        n = len(nums)
        if max(nums) - min(nums) <= k:
            return pow(2, n-1, mod=MOD)

        dp = [1, 1] + [0 for _ in range(n-1)]
        accum_dp = [0, 1, 2] + [0 for _ in range(n-1)] 
        cache = [(nums[0], 0)]
        left = -1
        for i in range(1, n):
            while cache and nums[i] - cache[0][0] > k:
                _, idx = cache.pop(0)
                left = max(left, idx)
            while cache and cache[-1][0] - nums[i] > k:
                _, idx = cache.pop()
                left = max(left, idx)
            bisect.insort(cache, (nums[i], i))
            dp[i+1] = (accum_dp[i+1] - accum_dp[left+1]) % MOD
            accum_dp[i+2] = (accum_dp[i+1] + dp[i+1]) % MOD
        return dp[-1] % MOD

提交代码评测得到：耗时964ms，占用内存29.5MB。