5259. Calculate Amount Paid in Taxes

class Solution:
    def calculateTax(self, brackets: List[List[int]], income: int) -> float:
        prev = 0
        res = 0
        for a, b in brackets:
            temp = a
            a = min(a, income)
            if (a - prev) < 0:
                return res
            res += (a - prev)*(b / 100)
            prev = temp
        return res