LeedCode_全排列

LeedCode_最大子序和

题目说明

给定一个没有重复数字的序列，返回其所有可能的全排列。
输入: [-2,1,-3,4,-1,2,1,-5,4],

输入: [1,2,3]
输出:
[
[1,2,3],
[1,3,2],
[2,1,3],
[2,3,1],
[3,1,2],
[3,2,1]
]

链接：https://leetcode-cn.com/problems/permutations
分析：回溯算法套路

void backpermute(vector<int> nums, vector<vector<int>>& res, vector<int>& answer)
{
	vector<int>::iterator it;
	if (answer.size() == nums.size())
	{
		res.push_back(answer);
		return;
	}
	for (int i = 0; i < nums.size(); i++)
	{
		it = find(answer.begin(), answer.end(), nums[i]);
		if (it == answer.end())
		{
			answer.push_back(nums[i]);
			backpermute(nums, res, answer);
			answer.pop_back();
		}
		else
		{
			continue;
		}
	}
	return;
}
vector<vector<int>> permute(vector<int>& nums) 
{
	vector<vector<int>> res;
	vector<int> temp;
	backpermute(nums, res, temp);
	return res;
}