Final Prices With a Special Discount in a Shop — LeetCode 1475 Python Solution

The problem

You are given an integer array prices where prices[i] is the price of the ith item in a shop. There is a special discount for items in the shop.

Example

Input

prices = [8,4,6,2,3]

Output

[4,2,4,2,3]

Explanation

For item 0 with price[0]=8 you will receive a discount equivalent to prices[1]=4, therefore, the final price you will pay is 8 - 4 = 4.

Python solution

class Solution:
    def finalPrices(self, prices: List[int]) -> List[int]:
        stk = []
        for i in reversed(range(len(prices))):
            x = prices[i]
            while stk and x < stk[-1]:
                stk.pop()
            if stk:
                prices[i] -= stk[-1]
            stk.append(x)
        return prices

Complexity

Pattern: Stack

When the most recent unresolved thing is the one that matters, use a stack. LeetCode 1475. Final Prices With a Special Discount in a Shop is filed here because LeetCode tags it Stack, which is the vocabulary this hub collects.

The stack guide has the Python template for the pattern and the 194 LeetCode problems that use it.

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