George - Algorithm

Here's the plan:

$1.$ Read $n$ (number of rooms).

$2.$ Initialize count = 0.

$3.$ For each of $n$ rooms, read occupancy and capacity.

$4.$ If capacity - occupancy >= 2, increment count.

$5.$ Print count. This is the filtering pattern. You stream items and count how many pass your test. Don't store items or remember decisions. Just maintain a running count. Each room passes or fails, update counter so. Notice you process data as you read it. Memory stays constant regardless of $n$. Check 10 rooms or 100000 rooms, you only need one counter.