Notes 📝
Initial trial -> Failed
idea 1.
1) get string, bring each string using "let i of s"
2) use switch condition statements,
for this, elements of s should be integer type
and then plus all of them
idea 2.
Use replace() functions and Regular Expression
There is targetStr()
Solution
✔ Use table, length and
✔ Use if statment in case that we have to subtract the first roman numeral from the next one
Keyword : table length case of subtract
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:
Ican be placed beforeV(5) andX(10) to make 4 and 9.Xcan be placed beforeL(50) andC(100) to make 40 and 90.Ccan be placed beforeD(500) andM(1000) to make 400 and 900.
Given a roman numeral, convert it to an integer.
Example 1:
Input: s = "III" Output: 3 Explanation: III = 3.
Example 2:
Input: s = "LVIII" Output: 58 Explanation: L = 50, V= 5, III = 3.
Example 3:
Input: s = "MCMXCIV" Output: 1994 Explanation: M = 1000, CM = 900, XC = 90 and IV = 4.
Constraints:
1 <= s.length <= 15scontains only the characters('I', 'V', 'X', 'L', 'C', 'D', 'M').- It is guaranteed that
sis a valid roman numeral in the range[1, 3999].