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$ curl repovive.com/roadmaps/data-structures/union-find/problem-swimming-in-rising-water

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Problem - Swimming in Rising Water - Union-Find | Data Structures | Repovive

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Data Structures19 sections · 729 units

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Problem - Swimming in Rising Water

Union-Find with sorting

Given an $n \times n$ grid of elevations, find the minimum time $t$ such that you can swim from $(0,0)$ to $(n-1,n-1)$ .

At time $t$ , you can swim to any cell with elevation $\leq t$ . Water rises uniformly across the grid. Example:

grid = [[0,2],
        [1,3]]

At $t=3$ , all cells are reachable. Answer: $3$ .

This combines Union-Find with time-based activation. Constraints: $n$ from $1$ to $50$ , elevations from $0$ to $n^2 - 1$ .

HannahHi! I'm Hannah. Let me know if you need help understanding anything!