Suppose we have a list of values called coins and another list called quantities of the same length. The value of ith coin is coins[i] and we currently have quantities[i] number of ith coin. We have to find number of distinct coin sum values we can get by using non-empty group of these coins.
So, if the input is like coins = [1, 2, 5] quantities = [1, 2, 1], then the output will be 10, as we can have the following distinct coin sums [1] = 1, [2] = 2, [1,2] = 3, [2,2] = 4, [5] = 5,[1,5] = 6, [2,5] = 7, [1,2,5] = 8, [2,2,5] = 9, [1,2,2,5] = 10.
To solve this, we will follow these steps:
Define a function rec() . This will take i, res
if i is same as size of coins , then return for k in range 0 to quantities[i] + 1, do cur := res + k * coins[i] insert cur into fres rec(i + 1, cur) From the main method, do the following: fres := a new set rec(0, 0) return size of fres - 1
Example
class Solution: def solve(self, coins, quantities): def rec(i, res): if i == len(coins): return for k in range(0, quantities[i] + 1): cur = res + k * coins[i] fres.add(cur) rec(i + 1, cur) fres = set() rec(0, 0) return len(fres) - 1 ob = Solution() coins = [1, 2, 5] quantities = [1, 2, 1] print(ob.solve(coins, quantities))
Input
[1, 2, 5], [1, 2, 1]
Output
10