do daily

Author: Zanger67

my-submissions/m2579 v1.py

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+class Solution:
+    def coloredCells(self, n: int) -> int:
+        return 1 + sum(layer for layer in range(4, n * 4, 4))

my-submissions/m2579 v2 o1 math solution.py

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+class Solution:
+    def coloredCells(self, n: int) -> int:
+        return 1 + 4 * n // 2 * (n - 1)

my-submissions/m2579.md

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+Notes
+
+```
+    n   output
+    1   1
+    2   1 + 4 = 5
+    3   1 + 4 + 8 = 13
+    4   1 + 4 + 8 + 12 = 25
+    5   1 + 4 + 8 + 12 + 16 = 41
+```
+
+The difference increases by 4 each time
+
+## V1
+
+Iterative $O(n)$
+
+## V2
+
+Math $O(1)$

my-submissions/m797.md

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+Since the edge is acyclic and directed, we do not have to worry about
+going back on our previous nodes

my-submissions/m797.py

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+class Solution:
+    def _dfs_helper(self, curr: int, n: int, edges: defaultdict, path: List[int] = None, output: List[List[int]] = None) -> List[List[int]] :
+        if output is None :
+            output: List[List[int]] = []
+
+        if path is None :
+            path = [curr]
+
+        if curr == n - 1 :
+            output.append(path.copy())
+            return
+
+        for e in edges[curr] :
+            path.append(e)
+            self._dfs_helper(e, n, edges, path, output)
+            path.pop()
+
+        return output
+        
+    def allPathsSourceTarget(self, graph: List[List[int]]) -> List[List[int]]:
+        return self._dfs_helper(0, len(graph), graph)