feat: add solutions to lc problems: No.1930 (#3924)

Author: rain84

solution/1900-1999/1930.Unique Length-3 Palindromic Subsequences/README.md

@@ -176,6 +176,54 @@ public class Solution {
 }
 ```
 
+#### TypeScript
+
+```ts
+export function countPalindromicSubsequence(s: string): number {
+    const cnt = new Map<string, [number, number]>();
+    const n = s.length;
+    let ans = 0;
+
+    for (let i = 0; i < n; i++) {
+        const ch = s[i];
+        if (cnt.has(ch)) cnt.get(ch)![1] = i;
+        else cnt.set(ch, [i, i]);
+    }
+
+    for (const [_, [i, j]] of cnt) {
+        if (i !== j) {
+            ans += new Set(s.slice(i + 1, j)).size;
+        }
+    }
+
+    return ans;
+}
+```
+
+#### JavaScript
+
+```js
+export function countPalindromicSubsequence(s) {
+    const cnt = new Map();
+    const n = s.length;
+    let ans = 0;
+
+    for (let i = 0; i < n; i++) {
+        const ch = s[i];
+        if (cnt.has(ch)) cnt.get(ch)[1] = i;
+        else cnt.set(ch, [i, i]);
+    }
+
+    for (const [_, [i, j]] of cnt) {
+        if (i !== j) {
+            ans += new Set(s.slice(i + 1, j)).size;
+        }
+    }
+
+    return ans;
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

solution/1900-1999/1930.Unique Length-3 Palindromic Subsequences/README_EN.md

@@ -168,6 +168,54 @@ public class Solution {
 }
 ```
 
+#### TypeScript
+
+```ts
+export function countPalindromicSubsequence(s: string): number {
+    const cnt = new Map<string, [number, number]>();
+    const n = s.length;
+    let ans = 0;
+
+    for (let i = 0; i < n; i++) {
+        const ch = s[i];
+        if (cnt.has(ch)) cnt.get(ch)![1] = i;
+        else cnt.set(ch, [i, i]);
+    }
+
+    for (const [_, [i, j]] of cnt) {
+        if (i !== j) {
+            ans += new Set(s.slice(i + 1, j)).size;
+        }
+    }
+
+    return ans;
+}
+```
+
+#### JavaScript
+
+```js
+export function countPalindromicSubsequence(s) {
+    const cnt = new Map();
+    const n = s.length;
+    let ans = 0;
+
+    for (let i = 0; i < n; i++) {
+        const ch = s[i];
+        if (cnt.has(ch)) cnt.get(ch)[1] = i;
+        else cnt.set(ch, [i, i]);
+    }
+
+    for (const [_, [i, j]] of cnt) {
+        if (i !== j) {
+            ans += new Set(s.slice(i + 1, j)).size;
+        }
+    }
+
+    return ans;
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

solution/1900-1999/1930.Unique Length-3 Palindromic Subsequences/Solution.js

@@ -0,0 +1,19 @@
+export function countPalindromicSubsequence(s) {
+    const cnt = new Map();
+    const n = s.length;
+    let ans = 0;
+
+    for (let i = 0; i < n; i++) {
+        const ch = s[i];
+        if (cnt.has(ch)) cnt.get(ch)[1] = i;
+        else cnt.set(ch, [i, i]);
+    }
+
+    for (const [_, [i, j]] of cnt) {
+        if (i !== j) {
+            ans += new Set(s.slice(i + 1, j)).size;
+        }
+    }
+
+    return ans;
+}

solution/1900-1999/1930.Unique Length-3 Palindromic Subsequences/Solution.ts

@@ -0,0 +1,19 @@
+export function countPalindromicSubsequence(s: string): number {
+    const cnt = new Map<string, [number, number]>();
+    const n = s.length;
+    let ans = 0;
+
+    for (let i = 0; i < n; i++) {
+        const ch = s[i];
+        if (cnt.has(ch)) cnt.get(ch)![1] = i;
+        else cnt.set(ch, [i, i]);
+    }
+
+    for (const [_, [i, j]] of cnt) {
+        if (i !== j) {
+            ans += new Set(s.slice(i + 1, j)).size;
+        }
+    }
+
+    return ans;
+}