罗马字符串转化成整数

Author: jccweb000

algorithms/mergeTwoLists/mergeTwoLists.js

@@ -1,3 +1,15 @@
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val, next) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.next = (next===undefined ? null : next)
+ * }
+ */
+/**
+ * @param {ListNode} list1
+ * @param {ListNode} list2
+ * @return {ListNode}
+ */
 var mergeTwoLists = function(list1, list2) {
   // 数组的解法
   // let targetList = list1;
@@ -9,6 +21,7 @@ var mergeTwoLists = function(list1, list2) {
   // return targetList;
 
   // 链表
+  // 每次传进来的是 ListNode
   if (list1 === null) return list2;
   if (list2 === null) return list1;
 
@@ -20,5 +33,3 @@ var mergeTwoLists = function(list1, list2) {
     return list2
   }
 };
-
-console.log(mergeTwoLists([1, 2, 3], [2, 3, 8]));

algorithms/romanToInt/romanToInt.js

@@ -0,0 +1,34 @@
+/**
+ * @param {string} s
+ * @return {number}
+ */
+ var romanToInt = function(s) {
+    const map = {
+      I: 1,
+      V: 5,
+      IX: 9,
+      X: 10,
+      XL: 40,
+      L: 50,
+      XC: 90,
+      C: 100,
+      CD: 400,
+      D: 500,
+      CM: 900,
+      M: 1000
+    };
+    let result = 0;
+    for (let i = 0; i < s.length;) {
+      // 两种情况，一位或者两位
+      if (i + 1 < s.length && map[s.substring(i, i+2)]) {
+        result += map[s.substring(i, i+2)];
+        i += 2;
+      } else {
+        result += map[s.substring(i, i+1)];
+        i++;
+      }
+    }
+
+    console.log(result);
+    return result;
+};