DaleStudy#280 Meeting Rooms II

Author: forest000014

meeting-rooms-ii/forest000014.java

@@ -0,0 +1,42 @@
+/*
+# Time Complexity: O(nlogn)
+# Space Complexity: O(n)
+*/
+
+class Solution {
+
+    private class Info {
+        int kind; // start = 0, end = 1
+        int time;
+
+        Info(int kind, int time) {
+            this.kind = kind;
+            this.time = time;
+        }
+    }
+    public int minMeetingRooms(int[][] intervals) {
+        int n = intervals.length;
+        List<Info> infos = new ArrayList<>();
+        for (int i = 0; i < n; i++) {
+            infos.add(new Info(0, intervals[i][0]));
+            infos.add(new Info(1, intervals[i][1]));
+        }
+
+        Collections.sort(infos, (o1, o2) -> {
+            if (o1.time == o2.time) {
+                return Integer.compare(o2.kind, o1.kind);
+            }
+            return Integer.compare(o1.time, o2.time);
+        });
+
+        int cnt = 0;
+        int ans = 0;
+        for (Info info : infos) {
+            if (info.kind == 0) cnt++;
+            else cnt--;
+            ans = Math.max(ans, cnt);
+        }
+
+        return ans;
+    }
+}