题解 | #dom 节点查找#

function commonParentNode(oNode1, oNode2) {
    if (oNode1 === oNode2) {
        return oNode1;
    }
    const parent1 = oNode1.parentNode;
    const parent2 = oNode2.parentNode;
    if (parent1 === oNode2 || parent1 === parent2) {
        return parent1;
    }
    else if (parent2 === oNode1) {
        return parent2;
    }
    return commonParentNode(parent1, parent2);
}