Easy

Quiz

#13 Roman to Integer

APPROACH

Roman numerals use seven symbols: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. A symbol of lesser value immediately before one of greater value is subtracted; otherwise it is added. Convert the given Roman numeral string to its integer value.

Example 1:

Symbol Value

I 1

V 5

X 10

L 50

C 100

D 500

M 1000

Example 2:

Input: s = "III"

Output: 3

Explanation: III = 3.

Example 3:

Input: s = "LVIII"

Output: 58

Explanation: L = 50, V= 5, III = 3.

Example 4:

Input: s = "MCMXCIV"

Output: 1994

Explanation: M = 1000, CM = 900, XC = 90 and IV = 4.

1 of 4

1:00

What is the optimal approach for this problem?