题解 | 牧场奶牛集合区域

1. 注意 L19 L20 即可。

import java.util.*;


public class Solution {
    public int[][] findGatheringAreas (int[] groups, int n) {
        if (n == 0) {
            return new int[0][0];
        }
        List<Integer> tmp = new ArrayList<>();
        Arrays.sort(groups);
        int l = 0;
        for (int r = 1; r < n; ++r) {
            if (groups[r] != groups[r - 1] + 1) {
                tmp.add(groups[l]);
                tmp.add(groups[r - 1]);
                l = r;
            }
        }
        tmp.add(groups[l]);
        tmp.add(groups[n - 1]);

        final int m = tmp.size() / 2;        
        int[][] ans = new int[m][2];
        for (int i = 0; i < m; i += 1) {
            ans[i][0] = tmp.get(2 * i);
            ans[i][1] = tmp.get(2 * i + 1);
        }
        return ans;
    }
}