From e8de164d9dd5009de05472ec861661e4db4f96ea Mon Sep 17 00:00:00 2001 From: mrb00l34n Date: Wed, 22 Jul 2015 11:31:38 -0400 Subject: [PATCH] Fixed pull request changes --- README.md | 2 +- .../coinchange_ways_challenge.ipynb | 18 ++++++------- .../coinchange_ways_solution.ipynb | 26 +++++++++---------- .../coinchange_ways/test_coinchange_ways.py | 8 +++--- 4 files changed, 27 insertions(+), 27 deletions(-) diff --git a/README.md b/README.md index 7fbd04a..db5f37f 100644 --- a/README.md +++ b/README.md @@ -216,7 +216,7 @@ Challenges, solutions, and unit tests are presented in the form of **IPython/Jup | Print all valid combinations of n-pairs of parentheses | [Contribute](https://github.com/donnemartin/interactive-coding-challenges/blob/master/CONTRIBUTING.md)│[Contribute](https://github.com/donnemartin/interactive-coding-challenges/blob/master/CONTRIBUTING.md) | | Implement a paint fill function | [Contribute](https://github.com/donnemartin/interactive-coding-challenges/blob/master/CONTRIBUTING.md)│[Contribute](https://github.com/donnemartin/interactive-coding-challenges/blob/master/CONTRIBUTING.md) | | Find all permutations to represent n cents, given 1, 5, 10, 25 cent coins | [Contribute](https://github.com/donnemartin/interactive-coding-challenges/blob/master/CONTRIBUTING.md)│[Contribute](https://github.com/donnemartin/interactive-coding-challenges/blob/master/CONTRIBUTING.md) | -| Find the number of ways to represent n cents given k arbitrary cent coins | [Challenge](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/recursion_dynamic/coin_change_ways/coinchange_ways_challenge.ipynb)│[Solution](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/recursion_dynamic/coin_change_ways/coinchange_ways_solution.ipynb) | +| Find the number of ways to represent n cents given an array of coins | [Challenge](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/recursion_dynamic/coin_change_ways/coinchange_ways_challenge.ipynb)│[Solution](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/recursion_dynamic/coin_change_ways/coinchange_ways_solution.ipynb) | | Add a challenge | [Contribute](https://github.com/donnemartin/interactive-coding-challenges/blob/master/CONTRIBUTING.md)│[Contribute](https://github.com/donnemartin/interactive-coding-challenges/blob/master/CONTRIBUTING.md) |
diff --git a/recursion_dynamic/coinchange_ways/coinchange_ways_challenge.ipynb b/recursion_dynamic/coinchange_ways/coinchange_ways_challenge.ipynb index ecabaa8..214bd8f 100644 --- a/recursion_dynamic/coinchange_ways/coinchange_ways_challenge.ipynb +++ b/recursion_dynamic/coinchange_ways/coinchange_ways_challenge.ipynb @@ -34,9 +34,9 @@ "source": [ "## Explanation\n", "\n", - "How many ways are there of making change for n, given k distinct coins? For example:\n", + "How many ways are there of making change for n, given an array of distinct coins? For example:\n", "\n", - "Input: n = 4, k = 2, coins = [1,2]\n", + "Input: n = 4, coins = [1, 2]\n", "\n", "Output: 3. 1+1+1+1, 1+2+1, 2+2, would be the ways of making change.\n", "\n", @@ -49,9 +49,9 @@ "source": [ "## Test Cases\n", "\n", - "* Input: n = 0, k = 2, coins = [1,2] -> Output: 0\n", - "* Input: n = 100, k = 3, coins = [1,2,3] -> Output: 884\n", - "* Input: n = 1000, k = 100, coins = [1,2,3...99,100] -> Output: 15658181104580771094597751280645\n" + "* Input: n = 0, coins = [1, 2] -> Output: 0\n", + "* Input: n = 100, coins = [1, 2, 3] -> Output: 884\n", + "* Input: n = 1000, coins = [1, 2, 3...99, 100] -> Output: 15658181104580771094597751280645\n" ] }, { @@ -78,7 +78,7 @@ }, "outputs": [], "source": [ - "def change_ways(n,k,coins):\n", + "def change_ways(n, coins):\n", " # TODO: Implement me\n", " return n" ] @@ -115,9 +115,9 @@ "class Challenge(object):\n", "\n", " def test_coinchange_ways(self,solution):\n", - " assert_equal(solution(0,2,[1,2]), 0)\n", - " assert_equal(solution(100,3,[1,2,3]), 884)\n", - " assert_equal(solution(1000,100,range(1,101)), 15658181104580771094597751280645)\n", + " assert_equal(solution(0, [1, 2]), 0)\n", + " assert_equal(solution(100, [1, 2, 3]), 884)\n", + " assert_equal(solution(1000, range(1, 101)), 15658181104580771094597751280645)\n", " print('Success: test_coinchange_ways')\n", "\n", "\n", diff --git a/recursion_dynamic/coinchange_ways/coinchange_ways_solution.ipynb b/recursion_dynamic/coinchange_ways/coinchange_ways_solution.ipynb index 424159c..c8706fd 100644 --- a/recursion_dynamic/coinchange_ways/coinchange_ways_solution.ipynb +++ b/recursion_dynamic/coinchange_ways/coinchange_ways_solution.ipynb @@ -33,7 +33,7 @@ "## Hints\n", "\n", "* Can you think of a way to build up to a solution?\n", - "* If there are 2 ways of making 3, and you are now given a coin of value v, how many ways can you make 3+v?\n", + "* If there are 2 ways of making 3, and you are now given a coin of value v, how many ways can you make 3 + v?\n", "* Can you think of a way to divide the problem into smaller subproblems?" ] }, @@ -46,15 +46,15 @@ "One possible solution using dynamic programming:\n", "* Create an array, s.t arr[i] = # of ways to make change for i\n", "* Initialize arr[0] = 1, arr[i>0] = 0\n", - "* For each coin, and for each index from coin to n, increment arr[i] by arr[i-coin]\n", + "* For each coin, and for each index from coin to n, increment arr[i] by arr[i - coin]\n", "\n", "How does this work?\n", - "* As we iterate through each coin, we are adding the ways of making arr[i-coin] to arr[i]\n", + "* As we iterate through each coin, we are adding the ways of making arr[i - coin] to arr[i]\n", "* If we have 2 ways of making 4, and are now iterating on a coin of value 3, there should be 2 ways of making 7.\n", "* We are essentially adding the coin we are iterating on to the # of ways of making arr[i].\n", "\n", "Complexity:\n", - "* Time: O(mn)\n", + "* Time: O(mn); let the number of coins be m. We iterate from arr[coin] -> arr[n], or ~ n operations on each coin, hence n*m. \n", "* Space: O(n)" ] }, @@ -73,12 +73,12 @@ }, "outputs": [], "source": [ - "def change_ways(n,k,coins):\n", - " arr = [1] + [0] * n\n", - " for coin in coins:\n", - " for i in xrange(coin,n + 1):\n", - " arr[i] += arr[i - coin]\n", - " return 0 if n == 0 else arr[n]" + "def change_ways(n, coins):\n", + " arr = [1] + [0] * n\n", + " for coin in coins:\n", + " for i in range(coin, n + 1):\n", + " arr[i] += arr[i - coin]\n", + " return 0 if n == 0 else arr[n]" ] }, { @@ -112,9 +112,9 @@ "class Challenge(object):\n", "\n", " def test_coinchange_ways(self,solution):\n", - " assert_equal(solution(0,2,[1,2]), 0)\n", - " assert_equal(solution(100,3,[1,2,3]), 884)\n", - " assert_equal(solution(1000,100,range(1,101)), 15658181104580771094597751280645)\n", + " assert_equal(solution(0, [1, 2]), 0)\n", + " assert_equal(solution(100, [1, 2, 3]), 884)\n", + " assert_equal(solution(1000, range(1, 101)), 15658181104580771094597751280645)\n", " print('Success: test_coinchange_ways')\n", "\n", "\n", diff --git a/recursion_dynamic/coinchange_ways/test_coinchange_ways.py b/recursion_dynamic/coinchange_ways/test_coinchange_ways.py index 0d8aef0..2e9d0a2 100644 --- a/recursion_dynamic/coinchange_ways/test_coinchange_ways.py +++ b/recursion_dynamic/coinchange_ways/test_coinchange_ways.py @@ -4,9 +4,9 @@ from nose.tools import assert_equal class Challenge(object): def test_coinchange_ways(self,solution): - assert_equal(solution(0,2,[1,2]), 0) - assert_equal(solution(100,3,[1,2,3]), 884) - assert_equal(solution(1000,100,range(1,101)), 15658181104580771094597751280645) + assert_equal(solution(0, [1, 2]), 0) + assert_equal(solution(100, [1, 2, 3]), 884) + assert_equal(solution(1000, range(1, 101)), 15658181104580771094597751280645) print('Success: test_coinchange_ways') @@ -16,4 +16,4 @@ def main(): if __name__ == '__main__': - main() \ No newline at end of file + main()