Problem - Jump Game II

Same setup, but find the minimum number of jumps to reach the end. Guaranteed reachable.

Example: [2,3,1,1,4]. Minimum jumps: $2$. Jump from $0$ to $1$ ($3$ steps available), then jump from $1$ to $4$.

This needs a more sophisticated greedy approach.

You cannot just track furthest.

You need to know when you are forced to jump.

Think BFS: each jump opens a new level of reachable positions.