07MagicMatrices

function solve(ar) {
    function sum(c) {
        return typeof c === 'number' ? ar.reduce((sum, ar) => sum + ar[c], 0) : c.reduce((sum, e) => sum + e, 0);
    }

    for (let i = 0; i < ar.length - 1; i++)
        if (sum(ar[i]) !== sum(ar[i + 1]) || sum(i) !== sum(i + 1))
            return false;

    return true;
}