James Pan

原题网址：https://leetcode.com/problems/permutations-ii/ Given a collection of numbers that might contain duplicates, return all possible unique permutations. For example, [1,1,2] have the followi

原题网址：https://leetcode.com/problems/n-queens-ii/ Follow up for N-Queens problem. Now, instead outputting board configurations, return the total number of distinct solutions. 方法一：深度优先搜索，使用一