Leetcode: Generalized Abbreviation

這道題肯定是DFS/Backtracking, 但是怎么DFS不好想，跟Leetcode: Remove Invalid Parentheses的backtracking很像。 Gen ...

Leetcode: Count of Range Sum

參考：https://leetcode.com/discuss/79083/share-my-solution First of all, let's look at the naiv ...