feat: update solution to lcci problem: No.01.01. Is Unique

Author: yanglbme

lcci/01.01.Is Unique/README.md

@@ -71,6 +71,26 @@ class Solution {
 }
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * @param {string} astr
+ * @return {boolean}
+ */
+ var isUnique = function(astr) {
+    let bitmap = 0;
+    for (let i = 0; i < astr.length; ++i) {
+        const pos = astr[i].charCodeAt() - 'a'.charCodeAt();
+        if ((bitmap & (1 << pos)) != 0) {
+            return false;
+        }
+        bitmap |= (1 << pos);
+    }
+    return true;
+};
+```
+
 ### **...**
 
 ```

lcci/01.01.Is Unique/README_EN.md

@@ -68,6 +68,26 @@ class Solution {
 }
 ```
 
+### **JavaScript**
+
+``` js
+/**
+ * @param {string} astr
+ * @return {boolean}
+ */
+ var isUnique = function(astr) {
+    let bitmap = 0;
+    for (let i = 0; i < astr.length; ++i) {
+        const pos = astr[i].charCodeAt() - 'a'.charCodeAt();
+        if ((bitmap & (1 << pos)) != 0) {
+            return false;
+        }
+        bitmap |= (1 << pos);
+    }
+    return true;
+};
+```
+
 ### **...**
 
 ```

lcci/01.01.Is Unique/Solution.js

@@ -0,0 +1,15 @@
+/**
+ * @param {string} astr
+ * @return {boolean}
+ */
+ var isUnique = function(astr) {
+    let bitmap = 0;
+    for (let i = 0; i < astr.length; ++i) {
+        const pos = astr[i].charCodeAt() - 'a'.charCodeAt();
+        if ((bitmap & (1 << pos)) != 0) {
+            return false;
+        }
+        bitmap |= (1 << pos);
+    }
+    return true;
+};