Solution.java

class Solution {
    private int[] p;

    public int maximumMinimumPath(int[][] grid) {
        int m = grid.length, n = grid[0].length;
        p = new int[m * n];
        List<int[]> q = new ArrayList<>();
        for (int i = 0; i < m; ++i) {
            for (int j = 0; j < n; ++j) {
                q.add(new int[] {grid[i][j], i, j});
                p[i * n + j] = i * n + j;
            }
        }
        q.sort((a, b) -> b[0] - a[0]);
        boolean[][] vis = new boolean[m][n];
        int[] dirs = {-1, 0, 1, 0, -1};
        int ans = 0;
        for (int i = 0; find(0) != find(m * n - 1); ++i) {
            int[] t = q.get(i);
            vis[t[1]][t[2]] = true;
            ans = t[0];
            for (int k = 0; k < 4; ++k) {
                int x = t[1] + dirs[k], y = t[2] + dirs[k + 1];
                if (x >= 0 && x < m && y >= 0 && y < n && vis[x][y]) {
                    p[find(x * n + y)] = find(t[1] * n + t[2]);
                }
            }
        }
        return ans;
    }

    private int find(int x) {
        if (p[x] != x) {
            p[x] = find(p[x]);
        }
        return p[x];
    }
}