322- 1 change exchange

Title: Given coins of different denominations of coins and a total amount of amount. We can write a function to calculate the minimum number of coins needed to make up the total amount. If there is no combination can be composed of any of a total amount of coins, return -1.

def coins_change(coins,amount):
    dp = [amount+1]*(amount+1)
    dp[0] = 0
    for i in range(1,amount+1):
        for j in range(len(coins)):
            if i>=coins[j]:
                dp[i] = min(dp[i],dp[i-coins[j]]+1)

    return -1 if dp[-1]>amount else dp[-1]

coins = [1,2,5]
amount = 11
print(coins_change(coins,amount))

　　Note:

Knapsack problem, the first sub-problems minimum number of coins per weight. dp is the minimum number of coins stored in the weight index. dp [i] = min (dp [i], dp [i-coins [j]] + 1) and is not placed into the current coin, minimum.