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 ...

Basic: Backtracking + pruning DP: refer to https://leetcode.com/problems/campus ...

原題鏈接在這里：https://leetcode.com/problems/maximum-length-of-a-concatenated-string-with-unique-characters ...

原題鏈接在這里：https://leetcode.com/problems/confusing-number-ii/ 題目： We can rotate digits by 180 degrees ...

原題鏈接在這里：https://leetcode.com/problems/brace-expansion/ 題目： A string S represents a list of words. ...

1、概念 回溯算法實際上一個類似枚舉的搜索嘗試過程，主要是在搜索嘗試過程中尋找問題的解，當發現已不滿足求解條件時，就“回溯”返回，嘗試別的路徑。 回溯法是一種選優搜索法，按選優條 ...

原題鏈接在這里：https://leetcode.com/problems/campus-bikes-ii/ 題目： On a campus represented as a 2D grid, t ...

Gradient Descent 機器學習中很多模型的參數估計都要用到優化算法，梯度下降是其中最簡單也用得最多的優化算法之一。梯度下降(Gradient Descent)[3]也被稱之為最快梯度(S ...

Given a set of candidate numbers (candidates) (without duplicates) and a target number (target), fin ...

原題鏈接在這里：https://leetcode.com/problems/path-with-maximum-gold/ 題目： In a gold mine grid of size m * ...