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interface Solution {    pick(target: number): number;}function Solution(nums: number[]): Solution {    const pos: Map<number, number[]> = new Map();    for (const [i, num] of nums.entries()) {        const indices: number[] = pos.get(num) ??            (() => {                const d: number[] = [];                pos.set(num, d);                return d;            })();        indices.push(i);    }    function pick(target: number): number {        const indices = pos.get(target);        if (!indices) {            throw new Error("not found:" + target);        }        return indices[Math.floor(Math.random() * indices.length)];    }    return { pick };}
export default Solution;