22w1: add 13 leetcode js solution

Author: swiftwind0405

README.md

@@ -429,7 +429,7 @@
 |16|[3Sum Closest](https://leetcode.com/problems/3sum-closest/)| |Medium|
 |15|[3Sum](https://leetcode.com/problems/3sum/)| [js](./algorithms/3Sum/3Sum.js) |Medium|
 |14|[Longest Common Prefix](https://leetcode.com/problems/longest-common-prefix/)| [js](./algorithms/longestCommonPrefix/longestCommonPrefix.js) |Easy|
-|13|[Roman to Integer](https://leetcode.com/problems/roman-to-integer/)| |Easy|
+|13|[Roman to Integer](https://leetcode.com/problems/roman-to-integer/)| [js](./algorithms/romanToInteger/solution.js) |Easy|
 |12|[Integer to Roman](https://leetcode.com/problems/integer-to-roman/)| |Medium|
 |11|[Container With Most Water](https://leetcode.com/problems/container-with-most-water/)| [js](./algorithms/containerWithMostWater/containerWithMostWater.js) |Medium|
 |10|[Regular Expression Matching](https://leetcode.com/problems/regular-expression-matching/)| |Hard|

algorithms/romanToInteger/solution.js

@@ -0,0 +1,23 @@
+/**
+ * @param {string} s
+ * @return {number}
+ */
+ var romanToInt = function (s) {
+    const map = {
+        I: 1,
+        V: 5,
+        X: 10,
+        L: 50,
+        C: 100,
+        D: 500,
+        M: 1000,
+    }
+    let array = s.split('').map(item => map[item]);
+    for (let x = 0, y = 1; x < array.length - 1; x++, y++) {
+        if (array[x] < array[y]) {
+            array[y] = array[y] - array[x]
+            array[x] = 0;
+        }
+    }
+    return array.reduce((accumulator, currentValue) => accumulator + currentValue, 0);
+};