p13 (JuliaCN#148)

Author: Moelf

src/unresolved/13.roman-to-integer.jl renamed to src/problems/13.roman-to-integer.jl

@@ -1,8 +1,8 @@
 # ---
 # title: 13. Roman to Integer
 # id: problem13
-# author: Tian Jun
-# date: 2020-10-31
+# author: Jerry Ling
+# date: 2021-12-13
 # difficulty: Easy
 # categories: Math, String
 # link: <https://leetcode.com/problems/roman-to-integer/description/>
@@ -95,5 +95,25 @@
 ## @lc code=start
 using LeetCode
 
+function roman_to_integer(s::AbstractString)
+    table = Dict(
+        'I'      =>       1,
+        'V'      =>       5,
+        'X'      =>       10,
+        'L'      =>       50,
+        'C'      =>       100,
+        'D'      =>       500,
+        'M'      =>       1000,
+    )
+
+    nums = [table[c] for c in s]
+
+    for idx = 1:lastindex(nums)-1
+        nums[idx] *= nums[idx] >= nums[idx+1] ? 1 : -1 
+    end
+
+    return sum(nums)
+end
+
 ## add your code here:
 ## @lc code=end

test/problems/13.roman-to-integer.jl

@@ -0,0 +1,7 @@
+@testset "13.roman-to-integer.jl" begin
+    @test roman_to_integer("III") == 3
+    @test roman_to_integer("IV") == 4
+    @test roman_to_integer("IX") == 9
+    @test roman_to_integer("LVIII") == 58
+    @test roman_to_integer("MCMXCIV") == 1994
+end