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export default function findPeakElement(nums: number[]): number {    if (nums.length == 1) {        return 0;    }    if (nums.length == 0) {        throw Error("empty array:");    }
    function get(index: number) {        return nums[index] ?? -Infinity;    }
    for (let i = 0, j = nums.length - 1; i <= j;) {        const m = Math.floor((i + j) / 2);        // console.log(i, j, m);        if (nums[m] > get(m + 1) && nums[m] > get(m - 1)) {            return m;        }
        if (nums[i] > get(i + 1) && nums[i] > get(i - 1)) {            return i;        }        if (nums[j] > get(j + 1) && nums[j] > get(j - 1)) {            return j;        }
        if (nums[m] < get(m + 1)) {            i = m + 1;        } else {            j = m - 1;        }    }    throw Error("accident");}