public int[][] kClosest(int[][] points, int K) {
int N = points.length;
int[] dists = new int[N];
for (int i = 0; i < N; ++i)
dists[i] = dist(points[i]);
Arrays.sort(dists);
int distK = dists[K-1];
int[][] ans = new int[K][2];
int t = 0;
for (int i = 0; i < N; ++i)
if (dist(points[i]) <= distK)
ans[t++] = points[i];
return ans;
}
public int dist(int[] point) {
return point[0] * point[0] + point[1] * point[1];
}
}