Jump Game

Greedy · Track the furthest safe reach · Stretch · about 22 min

Why it matters

A single evolving invariant can replace a seemingly exponential search.

How it connects

Your first greedy choice satisfied one child. Now maintain the strongest reachable future boundary.

Try first

As you scan index i, what one number tells you whether i was ever reachable?

Interview cue

The invariant is that every index up to furthestReach is reachable from earlier jumps.