Kth Largest in N Arrays

Find K-th largest element in N arrays.

Notice

You can swap elements in the array.

Example

Inn=2arrays[[9,3,2,4,7],[1,2,3,4,8]], the 3rd largest element is7.

Inn=2arrays[[9,3,2,4,8],[1,2,3,4,2]], the 1st largest element is9, 2nd largest element is8, 3rd largest element is7and etc.

public int KthInArrays(int[][] arrays, int k) {
    if(arrays == null || arrays.length == 0) {
        return 0;
    }
    PriorityQueue<Integer> maxHeap = new PriorityQueue<Integer>(k, Collections.reverseOrder());
    for(int i = 0; i < arrays.length; i++) {
        for(int j = 0; j < arrays[i].length; j++) {
            maxHeap.offer(arrays[i][j]);
        }
    }
    for(int i = 0; i < k - 1; i++) {
        maxHeap.poll();
    }
    return maxHeap.peek();
}