CODEWITHSUNDEEP
python
Jake
Jake

Reputation: 65

How to convert integers to numerals

The following code only converts the integers to numerals up to 1010. At that point, an error starts to occur.

class Solution:
    def intToRoman(self, num: int) -> str:
        numerals = {
            1: "I", 
            4: "IV", 
            5: "V", 
            10: "X",
            40: "XL",
            50: "L", 
            90: "XC",
            100: "C", 
            400: "CD",
            500: "D", 
            900: "CM",
            1000: "M"
        }
        
        output = ""

        for k,v in sorted(numerals.items(), reverse=True):
            while num >= k:
                output += v
                num -= k
        
        return output

I am looping through the numerals dictionary from greatest to least number wise and getting the ints (v) and the numerals (k)

Then I am using a while loop to see if the number is >= value (v)

After that output will be added to the numerals (k), and number (num) will be subtracted from the integer (v).

Then I return value.

I was thinking of doing something like an if statement maybe like:

if num < v:
   # code

Whenever I try adding that, I get a "Time Limit Exceeded"

Upvotes: 1

Views: 89

Answers (2)

Jake
Jake

Reputation: 65

I have optimized the code with all the suggestions posted on this. The following works with runtime coming in at 61 ms and memory usage of 14.2 MB.

You can use Tim Roberts method too (marked correct above)

Or you can use the following code:

My original method w/ added code and fixed options

class Solution:
    def intToRoman(self, num: int) -> str:
        numerals = {
            1: "I", 
            4: "IV", 
            5: "V",
            9: "IX",
            10: "X",
            40: "XL",
            50: "L", 
            90: "XC",
            100: "C", 
            400: "CD",
            500: "D", 
            900: "CM",
            1000: "M"
        }
        
        output = ""

        for k,v in sorted(numerals.items(), reverse=True):
            while num >= k:
                output += v
                num -= k
        
        return output

I appreciate everyone's help!

Upvotes: 2

Tim Roberts
Tim Roberts

Reputation: 54955

I'm not sure what you're seeing. When I fix your typos, this code produces good results.

However, in the interest of micro-optimization, I've replaced your unnecessary dictionary with a tuple that is already in order:

class Solution:
    numerals = (
        ("M", 1000),
        ("CM", 900),
        ("D", 500), 
        ("CD", 400), 
        ("C", 100), 
        ("XC", 90),
        ("L", 50), 
        ("XL", 40), 
        ("X", 10), 
        ("IX", 9),
        ("V", 5), 
        ("IV", 4), 
        ("I", 1), 
    )
        
    def intToRoman(self, num: int) -> str:
        output = ""

        for k,v in self.numerals:
            while num >= v:
                output += k 
                num -= v
        
        return output

s = Solution()
print( s.intToRoman( 10 ) )
print( s.intToRoman( 19 ) )
print( s.intToRoman( 4345 ) )

Upvotes: 2

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