From 98a149e41eca20f4ee3a2c031ee04987f64e34eb Mon Sep 17 00:00:00 2001 From: pradyotd Date: Wed, 20 Feb 2019 11:54:26 -0500 Subject: [PATCH] Update coin_change.py (#706) Cleanup PEP-8 , additional comments , using coin_val, instead of range and index. --- dynamic_programming/coin_change.py | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/dynamic_programming/coin_change.py b/dynamic_programming/coin_change.py index 0116df0c0..74d86661f 100644 --- a/dynamic_programming/coin_change.py +++ b/dynamic_programming/coin_change.py @@ -6,21 +6,26 @@ the given types of coins? https://www.hackerrank.com/challenges/coin-change/problem """ from __future__ import print_function + + def dp_count(S, m, n): + + # table[i] represents the number of ways to get to amount i table = [0] * (n + 1) - # Base case (If given value is 0) + # There is exactly 1 way to get to zero(You pick no coins). table[0] = 1 # Pick all coins one by one and update table[] values # after the index greater than or equal to the value of the # picked coin - for i in range(0, m): - for j in range(S[i], n + 1): - table[j] += table[j - S[i]] + for coin_val in S: + for j in range(coin_val, n + 1): + table[j] += table[j - coin_val] return table[n] + if __name__ == '__main__': print(dp_count([1, 2, 3], 3, 4)) # answer 4 print(dp_count([2, 5, 3, 6], 4, 10)) # answer 5