Create 0097-interleaving-string.swift

Author: drxlx

swift/0097-interleaving-string.swift

@@ -0,0 +1,27 @@
+/**
+ * Question Link: https://leetcode.com/problems/interleaving-string/
+ */
+
+class Solution {
+    func isInterleave(_ s1: String, _ s2: String, _ s3: String) -> Bool {
+        let s1 = Array(s1), s2 = Array(s2), s3 = Array(s3)
+        if s3.count != s1.count + s2.count {
+            return false
+        }
+        var dp = Array(repeating: false, count: s2.count + 1)
+        for i in 0..<s1.count + 1 {
+            for j in 0..<s2.count + 1 {
+                if i == 0 && j == 0 {
+                    dp[j] = true
+                } else if i == 0 {
+                    dp[j] = dp[j - 1] && s2[j - 1] == s3[i + j - 1]
+                } else if j == 0 {
+                    dp[j] = dp[j] && s1[i - 1] == s3[i + j - 1]
+                } else {
+                    dp[j] = (dp[j] && s1[i - 1] == s3[i + j - 1]) || (dp[j - 1] && s2[j - 1] == s3[i + j - 1])
+                }
+            }
+        }
+        return dp[s2.count]
+    }
+}