@@ -46,15 +46,13 @@ public List<int[]> getSkyline(int[][] buildings) {
 List<int[]> res = new ArrayList<>();
 int N = buildings.length;
 if (N == 0) return res;
-
+
 // xi, hi, L/R
-int[][] verts = new int[N * 2][4];
+int[][] verts = new int[N * 2][3];
 int t = 0;
-int f = 0;
 for (int[] b: buildings) {
-verts[t++] = new int[]{b[0], b[2], L, f};
-verts[t++] = new int[]{b[1], b[2], R, f};
-f++;
+verts[t++] = new int[]{b[0], b[2], L};
+verts[t++] = new int[]{b[1], b[2], R};
 }
 Comparator<int[]> comp1 = new Comparator<int[]>() {
 @Override
@@ -72,45 +70,29 @@ public int compare(int[] v1, int[] v2) {
 }
 };
 Arrays.sort(verts, comp1);
-
-Comparator<int[]> comp2 = (v1, v2) -> Integer.compare(v2[1], v1[1]);
-List<int[]> hs = new ArrayList<>();
+
+Comparator<Integer> comp2 = (h1, h2) -> Integer.compare(h2, h1);
+PriorityQueue<Integer> pq = new PriorityQueue<>(comp2);
 for (int[] vi: verts) {
 int xi = vi[0];
 int hi = vi[1];
 int Di = vi[2];
-int flag = vi[3];
 
-Collections.sort(hs, comp2);
 if (Di == L) { // L
-if (hs.isEmpty() || hs.get(0)[1] < hi) {
+if (pq.isEmpty() || pq.peek() < hi) {
 res.add(new int[]{xi, hi});
 }
-hs.add(vi);
+pq.add(hi);
 } else { // R
-int size = hs.size();
-for (int i=0; i<size; i++) {
-if (hs.get(i)[3] == flag) {
-hs.remove(i);
-break;
-}
-}
-if (hs.isEmpty() || hs.get(0)[1] < hi) {
-int y = hs.isEmpty() ? 0 : hs.get(0)[1];
+pq.remove(hi);
+if (pq.isEmpty() || pq.peek() < hi) {
+int y = pq.isEmpty() ? 0 : pq.peek();
 res.add(new int[]{xi, y});
 }
 }
 }
+
 return res;
 }
 
-
-
-
-
-
-
-
-
-
 }