https://leetcode.cn/contest/weekly-contest-349/

Q1 https://leetcode.cn/problems/neither-minimum-nor-maximum/solution/o1-shi-jian-zuo-fa-pythonjavacgo-by-endl-sa7h/ Q2 https://leetcode.cn/problems/lexicographically-smallest-string-after-substring-operation/solution/tan-xin-pythonjavacgo-by-endlesscheng-gm1d/ Q3 https://leetcode.cn/problems/collecting-chocolates/solution/qiao-miao-mei-ju-pythonjavacgo-by-endles-5ws2/ Q4 https://leetcode.cn/problems/maximum-sum-queries/solution/pai-xu-dan-diao-zhan-shang-er-fen-by-end-of9h/

视频讲解： https://www.bilibili.com/video/BV15V4y1m7Sb/?spm_id_from=333.337.search-card.all.click&vd_source=84c3c489cf545fafdbeb3b3a6cd6a112

00:01 Q1 O(1)做法 02:58 Q2 贪心 09:24 Q3 转换 31:58 Q4 单调栈 47:37 Q4 动态开点线段树