JSON Deep Equal — TypeScript

// Time:  O(n)
// Space: O(h)

// dfs
function areDeeplyEqual(o1: any, o2: any): boolean {
    if (o1 === o2) {
        return true;
    }
    if (typeof o1 !== 'object' || o1 === null || typeof o2 !== 'object' || o2 === null) {
        return false;
    }
    if (Array.isArray(o1) !== Array.isArray(o2)) {
        return false;
    }
    const keys1 = Object.keys(o1);
    const keys2 = Object.keys(o2);
    if (keys1.length !== keys2.length) {
        return false;
    }
    return keys1.every(key => areDeeplyEqual(o1[key], o2[key]));
};