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export default function binaryGap(n: number): number {    const binStr = n.toString(2);    let lastOneIdx = n,        max = 0;    for (let i = 0; i < binStr.length; i++) {        if (binStr.charAt(i) == "1") {            max = Math.max(max, i - lastOneIdx);            lastOneIdx = i;        }    }    return max;}