架构师训练营第八周作业

function mergedList(list1, list2) {
    if (!list1 || !list2) {
        return null;
    }
    // 让l1为长度较大的链表，l2为长度较小的链表
    const l1 = list1.length > list2.length ? list1 : list2;
    const l2 = list1.length <= list2.length ? list1 : list2;
    const m = l1.length;
    const n = l2.length;
    const d = m - n;
    for (let i = 0; i < n; i++) {
        if (l1[d + i] === l2[i]) {
            return l2[i];
        }
    }
    return null;
}