Merge pull request #1618 from YoungSeok-Choi/feature/week-13

[YoungSeok-Choi] Week 13 solutions

Author: SamTheKorean

meeting-rooms/YoungSeok-Choi.java

@@ -0,0 +1,39 @@
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+
+class Interval {
+    int start, end;
+
+    Interval(int start, int end) {
+        this.start = start;
+        this.end = end;
+    }
+}
+
+class Solution {
+
+    public boolean canAttendMeetings(List<Interval> intervals) {
+        Collections.sort(intervals, new Comparator<Interval>() {
+            @Override
+            public int compare(Interval i1, Interval i2) {
+                if (i1.start == i2.start) {
+                    return i1.end - i2.end;
+                }
+
+                return i1.start - i2.start;
+            }
+        });
+
+        int prevEnd = -987654321;
+        for (Interval anInt : intervals) {
+            if (anInt.start < prevEnd) {
+                return false;
+            }
+
+            prevEnd = anInt.end;
+        }
+
+        return true;
+    }
+}