数组·结合·enumeration 模式
9 道题目
模式页适合用来建立可复用解题框架。先识别题目特征，再按固定流程解释状态定义、转移和边界。
识别信号
- Asks if brute-force enumeration is acceptable given small constraints.
- Checks understanding of absolute difference and triplet conditions.
- Looking for awareness of pattern repetition and consecutive subarray detection.
解题流程
- 1. 明确窗口/状态定义
- 2. 更新状态并维护约束
- 3. 用边界样例验证
常见失分点
- Using <= instead of < for indices, causing duplicates or invalid triplets.
- Not verifying consecutive repetitions correctly, leading to false positives.
- Forgetting the radius cutoff, leading to including towers beyond reach.
推荐题单梯度
统计好三元组
Count Good Triplets requires identifying all triplets in an array that satisfy multiple absolute difference constraints …
重复至少 K 次且长度为 M 的模式
Determine if a subarray of length m repeats k or more consecutive times in a given integer array efficiently.
网络信号最好的坐标
Determine the coordinate with the maximum network quality by summing signal strengths from all reachable towers efficien…
收集巧克力
Calculate the minimum cost to collect all chocolate types using rotations and purchases in an array-based enumeration pa…
最长交替子数组
Find the longest alternating subarray in a given array of integers.
特殊元素平方和
Calculate the sum of squares of special elements in a 1-indexed array using index divisibility checks efficiently.
最大化数组末位元素的最少操作次数
Minimize the number of operations needed to maximize the last elements of two arrays with specific swaps.
找出峰值
Identify all peaks in a mountain array using direct array enumeration and strict neighbor comparisons efficiently.
三角形的最大高度
Find the maximum height of a triangle that can be formed using red and blue balls under given constraints.