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Abhishek Chaudhary

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Integer to Roman

Roman numerals are represented by seven different symbols: `I`, `V`, `X`, `L`, `C`, `D` and `M`.

Symbol Value
I 1
V 5
X 10
L 50
C 100
D 500
M 1000

For example, `2` is written as `II` in Roman numeral, just two one's added together. `12` is written as `XII`, which is simply `X + II`. The number `27` is written as `XXVII`, which is `XX + V + II`.

Roman numerals are usually written largest to smallest from left to right. However, the numeral for four is not `IIII`. Instead, the number four is written as `IV`. Because the one is before the five we subtract it making four. The same principle applies to the number nine, which is written as `IX`. There are six instances where subtraction is used:

• `I` can be placed before `V` (5) and `X` (10) to make 4 and 9.
• `X` can be placed before `L` (50) and `C` (100) to make 40 and 90.
• `C` can be placed before `D` (500) and `M` (1000) to make 400 and 900.

Given an integer, convert it to a roman numeral.

Example 1:

Input: num = 3
Output: "III"
Explanation: 3 is represented as 3 ones.

Example 2:

Input: num = 58
Output: "LVIII"
Explanation: L = 50, V = 5, III = 3.

Example 3:

Input: num = 1994
Output: "MCMXCIV"
Explanation: M = 1000, CM = 900, XC = 90 and IV = 4.

Constraints:

• `1 <= num <= 3999`

SOLUTION:

``````class Solution:
def intToRoman(self, num: int) -> str:
sym = {
1: "I",
5: "V",
10: "X",
50: "L",
100: "C",
500: "D",
1000: "M"
}
keys = list(sym.keys())
k = len(keys)
vals = []
i = 1
while num > 0:
curr = num % (10 ** i)
vals.insert(0, curr)
num -= curr
i += 1
print(vals)
op = ""
curr = 0
while curr < len(vals):
v = vals[curr]
if v in sym:
op += sym[v]
else:
found = False
for i in range(k):
for j in range(i + 1, k):
if v == keys[j] - keys[i]:
found = True
op += sym[keys[i]] + sym[keys[j]]
break