LeetCode046全排列

题目:

给定一个 没有重复 数字的序列，返回其所有可能的全排列。

示例:

• 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]
  ]

java:

public class Leetcode046 {

    static List<List<Integer>> res = new ArrayList<>();
    static LinkedList<Integer> path = new LinkedList<>();
    static boolean[] used;

    public static List<List<Integer>> permute(int[] nums) {
        if (nums.length == 0) {
            return res;
        }
        used = new boolean[nums.length];
        permuteHelper(nums);
        return res;
    }

    private static void permuteHelper(int[] nums) {
        if (path.size() == nums.length) {
            res.add(new ArrayList<>(path));
            return;
        }

        for (int i = 0; i < nums.length; i++) {
            if (used[i]) {
                continue;
            }
            used[i] = true;
            path.add(nums[i]);
            permuteHelper(nums);
            path.removeLast();
            used[i] = false;
        }
    }

    public static void main(String[] args) {
        int[] nums = {1, 2, 3};
        System.out.println(permute(nums));
    }
}

Go:

package LeetCode

var (
	result46 [][]int
	path46   []int
	used46   []bool
)

func Permute(nums []int) [][]int {
	result46 = make([][]int, 0)
	path46 = make([]int, 0, len(nums))
	used46 = make([]bool, len(nums))
	dfs46(nums, 0)
	return result46
}

func dfs46(nums []int, cur int) {
	if cur == len(nums) {
		tmp := make([]int, len(nums))
		copy(tmp, path46)
		result46 = append(result46, tmp)
	}

	for i := 0; i < len(nums); i++ {
		if !used46[i] {
			path46 = append(path46, nums[i])
			used46[i] = true
			dfs46(nums, cur+1)
			used46[i] = false
			path46 = path46[:len(path46)-1]
		}
	}
}


func main() {
	nums := []int{1, 2, 3}
	permute := LeetCode.Permute(nums)
	fmt.Println(permute)
}

吹凉的不是温度.

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