swift: add «452. Minimum Number of Arrows to Burst Balloons»

Signed-off-by: Matej Focko <me@mfocko.xyz>

swift/minimum-number-of-arrows-to-burst-balloons.swift

@@ -0,0 +1,19 @@
+class Solution {
+    func findMinArrowShots(_ points: [[Int]]) -> Int {
+        let points = points.sorted(by: { a, b in return a[0] < b[0] })
+
+        var usedArrows = 1
+        var maxX = points[0][1]
+
+        for point in points.dropFirst() {
+            if point[0] <= maxX {
+                maxX = min(maxX, point[1])
+            } else {
+                maxX = point[1]
+                usedArrows += 1
+            }
+        }
+
+        return usedArrows
+    }
+}