non-overlapping intervals solution

Author: yhkee0404

non-overlapping-intervals/yhkee0404.swift

@@ -0,0 +1,15 @@
+class Solution {
+    func eraseOverlapIntervals(_ intervals: [[Int]]) -> Int {
+        let intervals = intervals.sorted() { $0[1] < $1[1] } // T(n) = S(n) = O(nlogn)
+        var ans = 0
+        var end = -50_000
+        for se in intervals {
+            if se[0] < end {
+                ans += 1
+                continue
+            }
+            end = se[1]
+        }
+        return ans
+    }
+}