Arjiit
diff --git a/‎greedy/meetingRooms2.java
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+40Lines changed: 40 additions & 0 deletions b/‎greedy/meetingRooms2.java
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+40Lines changed: 40 additions & 0 deletions
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+/**
+ * Definition for an interval.
+ * public class Interval {
+ *     int start;
+ *     int end;
+ *     Interval() { start = 0; end = 0; }
+ *     Interval(int s, int e) { start = s; end = e; }
+ * }
+ */
+class Solution {
+    public int minMeetingRooms(Interval[] intervals) {
+        if (intervals.length == 0) {
+            return 0;
+        }
+        
+        // building min heap
+        PriorityQueue<Integer> allocator = new PriorityQueue<Integer>(intervals.length, new Comparator<Integer>() {
+            public int compare(Integer a, Integer b) {
+                return a - b;
+            }
+        });
+        
+        // sorting interval by startime
+        Arrays.sort(intervals, new Comparator<Interval>() {
+            public int compare(Interval a, Interval b) {
+                return a.start - b.start;
+            }
+        });
+        
+        allocator.add(intervals[0].end);
+        
+        for (int i=1; i<intervals.length; i++) {
+            if (intervals[i].start >= allocator.peek()) {
+                allocator.poll();
+            }
+        allocator.add(intervals[i].end);
+        }
+     return allocator.size();   
+    }
+}