Add solution 763

Author: vulgur

763_PartitionLabels.swift

@@ -0,0 +1,27 @@
+extension Character {
+    var ascii: Int {
+        return Int(self.unicodeScalars.first!.value)
+    }
+}
+class Solution {
+    func partitionLabels(_ S: String) -> [Int] {
+        // if S.isEmpty {
+        //     return [0]
+        // }
+        var map = Array(repeating: -1, count: 26+97)
+        for (i, c) in S.enumerated() {
+            map[c.ascii] = i
+        }
+        var result = [Int]()
+        var start = 0, end = 0
+        for (i, c) in S.enumerated() {
+            let right = map[c.ascii]
+            end = max(end, right)
+            if i == end {
+                result.append(end-start+1)
+                start = end + 1
+            }
+        }
+        return result
+    }
+}