# Leetcode 12 - Int to roman

`Note:`

- First, we need to list all
`atomic`

roman numbers, including variant like`900, 90, 40...`

. - For example, we list 90 instead of 80 is that 90 can be expressed as
`XC`

, but 80 is not`XXC`

but`LXXX`

. - While
`num`

is not 0, minus it with the`biggest atmoic roman num`

available. - Keep doing this till num is 0.

`Question:`

Roman numerals are represented by seven different symbols: `I`

, `V`

, `X`

, `L`

, `C`

, `D`

and `M`

.

1 | Symbol Value |

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 |

`Code:`

1 | /** |