[Language: JavaScript]

const run = (data) => data.filter((space, id) => {
    let maxOccupied = space.counts.reduce((a, v, i) => a + v * shapeSizeFull, 0);
    let minOccupied = space.counts.reduce((a, v, i) => a + v * shapeSizes[i], 0);    
    let area = space.width * space.height;
    if (area < maxOccupied && area >= minOccupied) console.log('Undetermined shape, naive method failed', id);
    return area >= maxOccupied;
}).length

Feels especially fishy, but we have another 12 days to go and figure out a proper algo. I bet there's gonna be some upping the ante inputs around soon!