Permutations
Description:
Given a collection of distinct numbers, return all possible permutations.
For example, [1,2,3] have the following permutations:
算法分析：解决这个问题，很容易想到树，一层层地生成。
因此我们可以考虑用递归的方式。
代码如下：
__author__ = 'andy' class Solution(object): def permute(self, nums): self.result = [] subList = [] self.cal(nums,subList) return self.result def cal(self,nums,subList): #如果子链表跟原链表等长，则加到结果中 if len(nums)==len(subList): self.result.append(subList[:]) #用递归的方式，得出组合 for a in nums: if a in subList: continue subList.append(a) self.cal(nums,subList) subList.remove(a) case = Solution() nums =[1,2,3] print(case.permute(nums)) 结果：
