dominique11 dipierro

Repovive Pre-Opening Contest/ Discussion

December 2, 2025 • 2 min read • 1 views

1A. Magical Stones

Just sort both arrays and then take the absolute sum of the differences between corresponding elements. This is optimal because any swap from this configuration will only increase the cost.

1B. Sweet Gifts

Iterate through every subarray in O(n^2). Within the loop, keep track of the frequency using a count[] array and its maximum value using an mx variable.

1C. Rayan's Journey

We have a graph composed of sparse roads and dense teleport-devices. We can model the dense edges using pseudo nodes for every type. A pseudo node of type t will only be joined with nodes of type t in such a way that:

The incoming edge from any node of type t will have zero weight.
The outgoing edge from the pseudo node will have weight C_t, and it will be connected to every node of the same type.

This construction results in m+2n edges and 2n nodes. We can then use Dijkstra's algorithm to find the shortest path.

1D. Stone Piles

1E. Two Paths

dominique11 dipierro

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2025-12-02

For D, we want, obviously, to calculate Grundy numbers for all N -- it is trivial that each number will be in {0, 1, 2}. By a...

2025-12-02

what do you mean by the states of 0,1,2 like what do they signify? Also after that how do you arrive at the catagorisation in...

2025-12-02

If anyone has solved D or E, please share some ideas. It will be really helpful for the community.