1from collections import deque
2
3def findFarmland(land):
4    m, n = len(land), len(land[0])
5    visited = [[False] * n for _ in range(m)]
6    results = []
7
8    for i in range(m):
9        for j in range(n):
10            if land[i][j] == 1 and not visited[i][j]:
11                queue = deque([(i, j)])
12                visited[i][j] = True
13                max_row, max_col = i, j
14
15                while queue:
16                    row, col = queue.popleft()
17                    max_row, max_col = max(max_row, row), max(max_col, col)
18
19                    for drow, dcol in [(0, 1), (1, 0)]:
20                        nrow, ncol = row + drow, col + dcol
21                        if nrow < m and ncol < n and land[nrow][ncol] == 1 and not visited[nrow][ncol]:
22                            visited[nrow][ncol] = True
23                            queue.append((nrow, ncol))
24
25                results.append([i, j, max_row, max_col])
26
27    return results

using System.Collections.Generic;

public class Solution {
    public int[][] FindFarmland(int[][] land) {
        int m = land.Length, n = land[0].Length;
        int[] parent = new int[m * n];
        int[] rank = new int[m * n];

        for (int i = 0; i < m * n; i++) {
            parent[i] = i;
        }

        int Find(int x) {
            if (parent[x] != x) {
                parent[x] = Find(parent[x]);
            }
            return parent[x];
        }

        void Union(int x, int y) {
            int rootX = Find(x);
            int rootY = Find(y);
            if (rootX != rootY) {
                if (rank[rootX] > rank[rootY]) {
                    parent[rootY] = rootX;
                } else if (rank[rootX] < rank[rootY]) {
                    parent[rootX] = rootY;
                } else {
                    parent[rootY] = rootX;
                    rank[rootX]++;
                }
            }
        }

        for (int i = 0; i < m; i++) {
            for (int j = 0; j < n; j++) {
                if (land[i][j] == 1) {
                    int index = i * n + j;
                    if (i > 0 && land[i-1][j] == 1) {
                        Union(index, (i-1) * n + j);
                    }
                    if (j > 0 && land[i][j-1] == 1) {
                        Union(index, i * n + (j-1));
                    }
                }
            }
        }

        var bounds = new Dictionary<int, int[]>();
        for (int i = 0; i < m; i++) {
            for (int j = 0; j < n; j++) {
                if (land[i][j] == 1) {
                    int root = Find(i * n + j);
                    if (!bounds.ContainsKey(root)) {
                        bounds[root] = new int[] { i, j, i, j };
                    } else {
                        bounds[root][0] = Math.Min(bounds[root][0], i);
                        bounds[root][1] = Math.Min(bounds[root][1], j);
                        bounds[root][2] = Math.Max(bounds[root][2], i);
                        bounds[root][3] = Math.Max(bounds[root][3], j);
                    }
                }
            }
        }

        var result = new List<int[]>(bounds.Values); 
        return result.ToArray();
    }
}