spiral-matrix

Author: se6816

spiral-matrix/se6816.java

@@ -0,0 +1,55 @@
+/**
+	구현을 통해 배열을 읽어들이는 방식
+	시간 복잡도 : O(N*M)
+	공간 복잡도 : O(N*M)
+*/
+class Solution {
+    int[] moveY = {1, 0, -1, 0};
+    int[] moveX = {0, -1, 0, 1};
+    int N;
+    int M;
+    public List<Integer> spiralOrder(int[][] matrix) {
+        N = matrix.length;
+        M = matrix[0].length;
+        boolean[][] visited = new boolean[N][M];
+        List<Integer> result = new ArrayList<>();
+        int curX = 0;
+        int curY = 0;
+        int direction = 0;
+        int count = 0;
+        visited[curX][curY] = true;
+        result.add(matrix[curX][curY]);
+
+        while(true) {
+            if(count == 4) {
+                break;
+            }
+            int tempX = curX + moveX[direction];
+            int tempY = curY + moveY[direction];
+            if(outOfIndex(tempX, tempY)) {
+                direction = (direction + 1) % 4;
+                count++;
+                continue;
+            }
+
+            if(visited[tempX][tempY]) {
+               direction = (direction + 1) % 4;
+               count++;
+               continue; 
+            }
+
+            curX = tempX;
+            curY = tempY;
+            result.add(matrix[curX][curY]);
+            visited[curX][curY] = true;
+
+            count = 0;
+        }
+
+        return result;
+    }
+    
+    public boolean outOfIndex(int x, int y) {
+        return x < 0 || x >= N || y < 0 || y >= M;
+    }
+}