Merge pull request #3340 from drxlx/1091-shortest-path-in-binary-matrix

Create 1091-shortest-path-in-binary-matrix.swift

Author: Ykhan799

swift/1091-shortest-path-in-binary-matrix.swift

@@ -0,0 +1,82 @@
+/**
+ * Question Link: https://leetcode.com/problems/shortest-path-in-binary-matrix/
+ */
+
+ class ListNode {
+    let val: [Int]
+    var next: ListNode?
+
+    init(_ val: [Int]) {
+        self.val = val
+    }
+}
+
+class Dequeue {
+    var head: ListNode?
+    var tail: ListNode?
+    var size = 0
+
+    func enqueue(_ val: [Int]) {
+        let node = ListNode(val)
+        if head == nil {
+            head = node
+            tail = node
+        } else {
+            tail?.next = node
+            tail = tail?.next
+        }
+
+        size += 1
+    }
+
+    func deque() -> [Int]? {
+        if head == nil {
+            return nil
+        }
+
+        let node = head
+        head = head?.next
+        if head == nil {
+            tail = nil
+        }
+
+        size -= 1
+        return node!.val
+    }
+}
+
+class Solution {
+    func shortestPathBinaryMatrix(_ grid: [[Int]]) -> Int {
+        let rows = grid.count
+        let cols = grid[0].count
+        var visit = Set<[Int]>()
+        var deque = Dequeue()
+        visit.insert([0, 0])
+        deque.enqueue([0, 0, 1])
+
+        while deque.size > 0 {
+            let val = deque.deque()!
+            let r = val[0]
+            let c = val[1]
+            let len = val[2]
+
+            if r < 0 || c < 0 || r == rows || c == cols || grid[r][c] == 1 {
+                continue
+            }
+            
+            if r == rows - 1 && c == cols - 1 {
+                return len
+            }
+
+            let directions = [(0, 1), (0, -1), (1, 0), (-1, 0), (-1, -1), (1, 1), (-1, 1), (1, -1)]
+            for (dr, dc) in directions {
+                if !visit.contains([r + dr, c + dc]) {
+                    deque.enqueue([r + dr, c + dc, len + 1])
+                    visit.insert([r + dr, c + dc])
+                }
+            }
+        }
+
+        return -1
+    }
+}