class Solution { public int[] smallestRange(List<List<Integer>> nums) { int rangeLeft = 0, rangeRight = Integer.MAX_VALUE; int minRange = rangeRight - rangeLeft; int max = Integer.MIN_VALUE; int size = nums.size(); int[] next = new int[size]; PriorityQueue<Integer> priorityQueue = new PriorityQueue<Integer>(new Comparator<Integer>() { public int compare(Integer index1, Integer index2) { return nums.get(index1).get(next[index1]) - nums.get(index2).get(next[index2]); } }); for (int i = 0; i < size; i++) { priorityQueue.offer(i); max = Math.max(max, nums.get(i).get(0)); } while (true) { int minIndex = priorityQueue.poll(); int curRange = max - nums.get(minIndex).get(next[minIndex]); if (curRange < minRange) { minRange = curRange; rangeLeft = nums.get(minIndex).get(next[minIndex]); rangeRight = max; } next[minIndex]++; if (next[minIndex] == nums.get(minIndex).size()) { break; } priorityQueue.offer(minIndex); max = Math.max(max, nums.get(minIndex).get(next[minIndex])); } return new int[]{rangeLeft, rangeRight}; }}
