Dynamical Programming / Greedy + DFS, Math 三種策略求解 Leetcode 279. Perfect Squares
分別用 2D Prefix Sum 與 Sorting + Greedy 求解 Leetcode 3027. Find the Number of Ways to Place People II
Prefix Sum 法求解 Leetcode 3026. Maximum Good Subarray Sum
Counting 結合 Sliding Window 法求解 Leetcode 76. Minimum Window Substring
用動態規劃法 (Dynamical programming) 求解 Leetcode 1043. Partition Array for Maximum Sum 並對區間極值的求法優化
用 brute force 與 迴圈 求解 Leetcode 1291. Sequential Digits
