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function pairSums(nums: number[], target: number): number[][] {    const res: number[][] = [];    const map = new Map<number, number>();    for (const num of nums) {        const key = target - num;        const value = map.get(key);
        if (map.has(key) && Number(value) > 0) {            res.push([key, num]);            map.set(key, (map.get(key) ?? 0) - 1);        } else {            map.set(num, (map.get(num) ?? 0) + 1);        }    }    return res;}export default pairSums;