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export default function nextPermutation(nums: number[]): void {    if (nums.length === 0) return;    let firstIndex = -1;    for (let i = nums.length - 1; i > 0; i--) {        if (nums[i] > nums[i - 1]) {            firstIndex = i - 1;            break;        }    }    if (firstIndex === -1) {        nums.reverse();        return;    }    let secondIndex = -1;    for (let i = nums.length - 1; i >= 0; i--) {        if (nums[i] > nums[firstIndex]) {            secondIndex = i;            break;        }    }    [nums[firstIndex], nums[secondIndex]] = [        nums[secondIndex],        nums[firstIndex],    ];    reverse(nums, firstIndex + 1, nums.length - 1);}
function reverse(nums: number[], arg1: number, arg2: number) {    while (arg1 < arg2) {        [nums[arg1], nums[arg2]] = [nums[arg2], nums[arg1]];        arg1++;        arg2--;    }}