삼각 달팽이

Author: co3oing

Programmers/삼각 달팽이.swift

@@ -0,0 +1,36 @@
+import Foundation
+
+func solution(_ n:Int) -> [Int] {
+    var map = Array(repeating: Array(repeating: 0, count: n+1), count: n+1)
+    var dy = [1, 0, -1]
+    var dx = [0, 1, -1]
+    var dPointer = 0
+    var y = -1
+    var x = 0
+    var nCount = n
+    var num = 1
+    
+    // 달팽이 채우기
+    while nCount >= 1 {
+        for i in 0..<nCount {
+            y += dy[dPointer]
+            x += dx[dPointer]
+            map[y][x] = num
+            num += 1
+        }
+        nCount -= 1
+        dPointer = (dPointer + 1) % 3
+    }
+    
+    // 새로운 배열 만들기
+    var answer: [Int] = []
+    for i in 0..<n {
+        for j in 0..<n {
+            if map[i][j] != 0 {
+                answer.append(map[i][j])
+            }
+        }
+    }
+    
+    return answer
+}