Polish tree dfs challenge and solution (#78)

Update constraints and algorithm discussion.
This commit is contained in:
Donne Martin 2016-06-25 08:30:02 -04:00 committed by GitHub
parent c7854b69cc
commit 884bbe4870
2 changed files with 21 additions and 18 deletions

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@ -18,7 +18,7 @@
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"## Problem: Implement depth-first searches (in-order, pre-order, post-order traversals) on a binary tree.\n", "## Problem: Implement depth-first traversals (in-order, pre-order, post-order) on a binary tree.\n",
"\n", "\n",
"* [Constraints](#Constraints)\n", "* [Constraints](#Constraints)\n",
"* [Test Cases](#Test-Cases)\n", "* [Test Cases](#Test-Cases)\n",
@ -34,6 +34,10 @@
"## Constraints\n", "## Constraints\n",
"\n", "\n",
"* Can we assume we already have a Node class with an insert method?\n", "* Can we assume we already have a Node class with an insert method?\n",
" * Yes\n",
"* What should we do with each node when we process it?\n",
" * Call an input method `visit_func` on the node\n",
"* Can we assume this fits in memory?\n",
" * Yes" " * Yes"
] ]
}, },
@ -203,21 +207,21 @@
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@ -18,7 +18,7 @@
"cell_type": "markdown", "cell_type": "markdown",
"metadata": {}, "metadata": {},
"source": [ "source": [
"## Problem: Implement depth-first searches (in-order, pre-order, post-order traversals) on a binary tree.\n", "## Problem: Implement depth-first traversals (in-order, pre-order, post-order) on a binary tree.\n",
"\n", "\n",
"* [Constraints](#Constraints)\n", "* [Constraints](#Constraints)\n",
"* [Test Cases](#Test-Cases)\n", "* [Test Cases](#Test-Cases)\n",
@ -34,6 +34,10 @@
"## Constraints\n", "## Constraints\n",
"\n", "\n",
"* Can we assume we already have a Node class with an insert method?\n", "* Can we assume we already have a Node class with an insert method?\n",
" * Yes\n",
"* What should we do with each node when we process it?\n",
" * Call an input method `visit_func` on the node\n",
"* Can we assume this fits in memory?\n",
" * Yes" " * Yes"
] ]
}, },
@ -67,6 +71,10 @@
"\n", "\n",
"## Test Cases\n", "## Test Cases\n",
"\n", "\n",
"Note:\n",
"\n",
"* This following are all forms of depth-first traversals\n",
"\n",
"### In-Order Traversal\n", "### In-Order Traversal\n",
"\n", "\n",
"* Recursively call in-order traversal on the left child\n", "* Recursively call in-order traversal on the left child\n",
@ -77,9 +85,6 @@
"* Time: O(n)\n", "* Time: O(n)\n",
"* Space: O(m), where m is the recursion depth, or O(1) if using an iterative approach\n", "* Space: O(m), where m is the recursion depth, or O(1) if using an iterative approach\n",
"\n", "\n",
"Note:\n",
"* This is a form of a depth-first traversal\n",
"\n",
"### Pre-Order Traversal\n", "### Pre-Order Traversal\n",
"\n", "\n",
"* Visit the current node\n", "* Visit the current node\n",
@ -90,9 +95,6 @@
"* Time: O(n)\n", "* Time: O(n)\n",
"* Space: O(m), where m is the recursion depth, or O(1) if using an iterative approach\n", "* Space: O(m), where m is the recursion depth, or O(1) if using an iterative approach\n",
"\n", "\n",
"Note:\n",
"* This is a form of a depth-first traversal\n",
"\n",
"### Post-Order Traversal\n", "### Post-Order Traversal\n",
"\n", "\n",
"* Recursively call post-order traversal on the left child\n", "* Recursively call post-order traversal on the left child\n",
@ -101,10 +103,7 @@
"\n", "\n",
"Complexity:\n", "Complexity:\n",
"* Time: O(n)\n", "* Time: O(n)\n",
"* Space: O(m), where m is the recursion depth, or O(1) if using an iterative approach\n", "* Space: O(m), where m is the recursion depth, or O(1) if using an iterative approach"
"\n",
"Note:\n",
"* This is a form of a depth-first traversal"
] ]
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@ -279,7 +278,7 @@
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