Create 0139-word-break.swift

Author: drxlx

swift/0139-word-break.swift

@@ -0,0 +1,20 @@
+class Solution {
+    func wordBreak(_ s: String, _ wordDict: [String]) -> Bool {
+        var s = Array(s)
+        var dp = [Bool](repeating: false, count: s.count + 1)
+        dp[s.count] = true
+
+        for i in stride(from: s.count - 1, to: -1, by: -1) {
+            for w in wordDict {
+                if i + w.count <= s.count && String(s[i..<(i + w.count)]) == w {
+                    dp[i] = dp[i + w.count]
+                }
+                if dp[i] {
+                    break
+                }
+            }
+        }
+
+        return dp[0]
+    }
+}