72. Edit Distance
- By
Wayne
When solving this problem, we must first observe how word1 becomes word2. Taking Example1 as an example, the lower left figure lists the distance from “horse” to “ros”.
1048. Longest String Chain
- By
In this problem, wordA is a predecessor of wordB which means we only need to insert a letter in wordA to make it the same as wordB.
Priority Queue & Heap
- By
Priority queue is a very useful data structure. It can provide the maximum or minimum value in constant time.
Binary Search Tree
- By
Binary search tree (BST) is a binary tree. It provides some useful operations including search, insert, delete, minimum, maximum, successor and predecessor.
1105. Filling Bookcase Shelves
- By
What this problem needs to solve is to calculate the minimum possible height of the bookshelf after placing all the books into the bookshelf.
62. Unique Paths
- By
This problem asks us to calculate the total number of all possible paths from the top-left corner to the bottom-right corner. We can observe that to go from the top-left corner to the bottom-right corner, the robot can only go right or down.
638. Shopping Offers
- By
We can use backtracking to find all the purchase combinations, and then take the lowest price.
39. Combination Sum
- By
This problem asks us to list all possible combinations, so we can use backtracking to find them. However, we must avoid finding duplicated combinations.
22. Generate Parentheses
- By
This problem asks us to list all possible combinations of parentheses, so we can use backtracking to solve it.
17. Letter Combinations of a Phone Number
- By
This problem asks us to list all possible strings, so we can think of using backtracking to solve it.
