摘要： Follow up for "Remove Duplicates": What if duplicates are allowed at most twice? For example, Given sorted array A = [1,1,1,2,2,3], Your function shou 阅读全文

摘要： Adopted approach: Notice that in line 11, you should create a copy of current path, and add it to res. Otherwise, it'll be edited later, and be wiped 阅读全文

摘要： Given two integers n and k, return all possible combinations of k numbers out of 1 ... n.For example,If n = 4 and k = 2, a solution is:[ [2,4], [3,4... 阅读全文