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import { uniqBy } from "../deps.ts";
export default function permuteUnique(nums: number[]): number[][] {    if (nums.length == 0) {        return [];    }    if (nums.length == 1) {        return [nums];    }
    const result: number[][] = [];
    permute_index(nums, (numsres: number[]) => {        result.push(numsres);    });    return uniqBy(result, (a: number[]) => Array.prototype.join.call(a, ","));}
function permute_index(nums: number[], output: (indexs: number[]) => void) {    const k = nums.length;    if (k === 0) {        return;    }    if (k === 1) {        output([0].map((v) => nums[v]));        return;    }
    permute_index(nums.slice(0, -1), (indexs) => {        const arrays: number[][] = [];        for (let i = 0; i < indexs.length + 1; i++) {            const b = Array.from(indexs);            b.splice(i, 0, nums.slice(-1)[0]);            arrays.push(b);        }
        for (            const res of uniqBy(                arrays,                (a: number[]) => Array.prototype.join.call(a, ","),            )        ) {            output(res);        }    });}