js实现输入：nums = 123输出：123132213231312321

function permute(nums) { let result = [];

function backtrack(tempArr) { if (tempArr.length === nums.length) { result.push([...tempArr]); } else { for (let i = 0; i < nums.length; i++) { if (!tempArr.includes(nums[i])) { tempArr.push(nums[i]); backtrack(tempArr); tempArr.pop(); } } } }

backtrack([]);

return result; }

console.log(permute([1, 2, 3])); // 输出：[[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]]