Leetcode:46.全排列

var permute = function(nums) {
    //用于判断是否标记
    let use = {};
    //保存结果
    let ans = [];
    function dfs(path)
    {
        //递归边界
        if(path.length==nums.length)
        {
            ans.push(path.slice());
            return ;
        }
        //递归选择
        for(let i = 0; i < nums.length; i++)
        {
            if(use[i])
                continue;
            path.push(nums[i]);
            use[i] = true;
            dfs(path);
            path.pop();
            use[i] = false;
        }
    }
    dfs([])
    return ans;
};