Integer to Roman

"""
Use a greedy approach by iterating over Roman values from largest to smallest, repeatedly subtracting the biggest possible value and appending its symbol.
Subtractive cases like 4 (IV), 9 (IX), 40 (XL), etc., are pre-stored in the mapping to naturally handle special Roman numeral rules.
"""
class Solution:
    def intToRoman(self, num: int) -> str:
        dict = {1000:'M',900:'CM',500:'D',400:'CD',100:'C',90:'XC',50:'L',40:'XL',10:'X',9:'IX',5:'V',4:'IV',1:'I'}
        print(dict)
        ans=''
        while num>0:
            for i in dict.keys():
                if i<=num:
                    ans+=dict[i]
                    num-=i
                    break
        return ans