problems(swift): add “1582. Special Positions in a Binary Matrix”

Signed-off-by: Matej Focko <mfocko@redhat.com>

swift/special-positions-in-a-binary-matrix.swift

@@ -0,0 +1,25 @@
+class Solution {
+    func numSpecial(_ mat: [[Int]]) -> Int {
+        let m = mat.count
+        let n = mat[0].count
+
+        var rows: [Int] = Array(repeating: 0, count: m)
+        var cols: [Int] = Array(repeating: 0, count: n)
+
+        for (y, x) in (0..<m).flatMap { y in (0..<n).map {x in (y, x) } } {
+            if mat[y][x] == 1 {
+                rows[y] += 1
+                cols[x] += 1
+            }
+        }
+
+        var count = 0
+        for (y, x) in (0..<m).flatMap { y in (0..<n).map {x in (y, x) } } {
+            if mat[y][x] == 1 && rows[y] == 1 && cols[x] == 1 {
+                count += 1
+            }
+        }
+
+        return count
+    }
+}