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 } }