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export default function removeDuplicates(nums: number[]): number {    if (nums.length === 0) return 0;    const s = new Map<number, number>();    nums.forEach((v) => {        const count = Math.min(2, 1 + (s.get(v) ?? 0));
        s.set(v, count);    });    let index = 0;    for (const [n, c] of s.entries()) {        for (let i = 0; i < c; i++) {            nums[index] = n;
            index++;        }    }    const length = index;    return length;}