Function permute

go/0046-permutations.go:3–25

(nums []int)

package main

func permute(nums []int) [][]int {
	n := len(nums)
	ans := make([][]int, 0)
	curr := make([]int, 0, n)
	vis := make(map[int]int)
	var backtrack func(idx int)
	backtrack = func(idx int) {
		if len(curr) == n {
			ans = append(ans, append([]int{}, curr...))
		}
		for i := 0; i < n; i++ {
			if vis[i] == 0 {
				vis[i]++
				curr = append(curr, nums[i])
				backtrack(i + 1)
				curr = curr[:len(curr)-1]
				vis[i]--
			}
		}
	}
	backtrack(0)
	return ans
}