Merge pull request #1635 from CodingTestStudy2/최원준

[최원준] Day05

Author: github-actions[bot]

leetcode3/최원준/498. Diagonal Traverse.py

@@ -0,0 +1,58 @@
+#
+
+'''
+1. 아이디어 :
+-
+
+2. 시간복잡도 :
+    O(n * m)
+
+3. 자료구조/알고리즘 :
+-
+
+'''
+
+class Solution:
+    def findDiagonalOrder(self, mat: List[List[int]]) -> List[int]:
+        ans = []
+        n = len(mat)
+        m = len(mat[0])
+
+        def get_next(x: int, y: int, going_up: bool):
+            if going_up:
+                if x == 0:
+                    if y == m - 1:
+                        return [x + 1, y]
+                    else:
+                        return [x, y + 1]
+                elif y == m - 1:
+                    return [x + 1, y]
+                else:
+                    return [x - 1, y + 1]
+
+            else: 
+                if y == 0:
+                    if x == n - 1:
+                        return [x, y + 1]
+                    else:
+                        return [x + 1, y]
+                elif x == n - 1:
+                    return [x, y + 1]
+                else:
+                    return [x + 1, y - 1]
+
+        x = y = 0
+        going_up = True
+
+        for _ in range(n * m):
+            ans.append(mat[x][y])
+            nx, ny = get_next(x, y, going_up)
+
+            if nx != x - 1 and nx != x + 1:
+                going_up = not going_up
+            elif ny != y - 1 and ny != y + 1:
+                going_up = not going_up
+
+            x, y = nx, ny
+
+        return ans