feat: add typescript solution to lc problem: No.1915.Number of Wonderful Substrings (doocs#483)

Author: zhaocchen

solution/1900-1999/1915.Number of Wonderful Substrings/README.md

@@ -71,6 +71,8 @@
 
 <!-- 这里可写通用的实现逻辑 -->
 
+状态压缩 + 前缀和
+
 <!-- tabs:start -->
 
 ### **Python3**
@@ -89,6 +91,32 @@
 
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * @param {string} word
+ * @return {number}
+ */
+var wonderfulSubstrings = function(word) {
+    let n = 1 << 10;
+    let counts = new Array(n).fill(0);
+    counts[0] = 1;
+    let pre = 0;
+    let ans = 0;
+    for (let c of word) {
+        let cur = c.charCodeAt(0) - 'a'.charCodeAt(0);
+        pre ^= (1 << cur);
+        ans += counts[pre];
+        for (let i = 1; i < n; i <<= 1) {
+            ans += counts[pre ^ i];
+        }
+        ++counts[pre];
+    }
+    return ans;
+};
+```
+
 ### **...**
 
 ```

solution/1900-1999/1915.Number of Wonderful Substrings/README_EN.md

@@ -79,6 +79,32 @@
 
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * @param {string} word
+ * @return {number}
+ */
+var wonderfulSubstrings = function(word) {
+    let n = 1 << 10;
+    let counts = new Array(n).fill(0);
+    counts[0] = 1;
+    let pre = 0;
+    let ans = 0;
+    for (let c of word) {
+        let cur = c.charCodeAt(0) - 'a'.charCodeAt(0);
+        pre ^= (1 << cur);
+        ans += counts[pre];
+        for (let i = 1; i < n; i <<= 1) {
+            ans += counts[pre ^ i];
+        }
+        ++counts[pre];
+    }
+    return ans;
+};
+```
+
 ### **...**
 
 ```

solution/1900-1999/1915.Number of Wonderful Substrings/Solution.js

@@ -0,0 +1,21 @@
+/**
+ * @param {string} word
+ * @return {number}
+ */
+ var wonderfulSubstrings = function(word) {
+    let n = 1 << 10;
+    let counts = new Array(n).fill(0);
+    counts[0] = 1;
+    let pre = 0;
+    let ans = 0;
+    for (let c of word) {
+        let cur = c.charCodeAt(0) - 'a'.charCodeAt(0);
+        pre ^= (1 << cur);
+        ans += counts[pre];
+        for (let i = 1; i < n; i <<= 1) {
+            ans += counts[pre ^ i];
+        }
+        ++counts[pre];
+    }
+    return ans;
+};