20240619 2288 - Medium - array

2288. Apply Discount to Prices

class Solution:
    def discountPrices(self, sentence: str, discount: int) -> str:
        def getPriceAfterDiscount(num):
            return str(print("%.2f" % (num * (discount / 100))))
        def isDigit(c):
            return ord("0") < ord(c) < ord("9")
        res = ""
        i = 0
        while i < len(sentence):
            if sentence[i] == "$":
                res += sentence[i]
                tmpi = i
                i += 1
                valid = True
                num = 0
                ni = 10
                while i < len(sentence):
                    if isDigit(sentence[i]):
                        # print(num, ni, int(sentence[i]))
                        num = num * ni + int(sentence[i])
                        i += 1
                    elif sentence[i] == " ":
                        valid = True
                        i += 1
                        break
                    else:
                        valid = False
                        i += 1
                        while i < len(sentence) and sentence[i] != " ":
                            i += 1
                        break
                    
                if valid and tmpi + 1 != i:
                    res += getPriceAfterDiscount(num) + " "
                    print(num)
            else:
                res += sentence[i]
            # space or lowercase character
            i += 1
        return res

solution

split sentence by space
find the "$" and then the digit

class Solution:
    def discountPrices(self, sentence: str, discount: int) -> str:
        d = 1 - discount / 100
        a = sentence.split(' ')
        for i, w in enumerate(a):
            if w[0] == '$' and w[1:].isdigit():
                a[i] = f"${int(w[1:]) * d :.2f}"
        return ' '.join(a)

solution​

solution