Today I am going to show how to solve the Leetcode Roman to Integer algorithm problem.
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.
SKP's Algorithms and Data Structures #1. My Article Series on Algorithms and Data Structures in a Sort of 'Programming Language Agnostic Way'. Few of the Algorithms and Data Structures in C, Few in C++, and Others in Core Java.
Algorithms and Data Structures for JavaScript Engineers: Big O notation, Merge Sort, Median value, Quick Sort, Interfaces, Set, Map, Stack, Queue, ArrayList, LinkedList, Binary Search Tree (BST), AVL tree, HASH TABLE, Functional Programming Overview, Map Function Naive Implementation, Reduce Function Naive Implementation, Filter Function Naive Implementation
This particular concept is identified as one of the most important concepts in software engineering, and that became a primary checkpoint for most of the top-level companies.
Understanding concepts such as algorithmic complexity and proper use of data structures will enable you to write more optimal code. I will list a few tools you will have under your tool-belt after taking a typical algorithms course.
JavaScript implementation of data-structures and algorithms mentioned in this playlist may be found here https://github.com/trekhleb/javascript-algorithms