From 11b719097b44ef880c30148ac48803a8f08c0cc8 Mon Sep 17 00:00:00 2001
From: chayan das <110921638+Chayandas07@users.noreply.github.com>
Date: Sat, 4 Jan 2025 20:32:17 +0530
Subject: [PATCH] Create 1930. Unique Length-3 Palindromic Subsequences1

---
 ... Unique Length-3 Palindromic Subsequences1 | 33 +++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 1930. Unique Length-3 Palindromic Subsequences1

diff --git a/1930. Unique Length-3 Palindromic Subsequences1 b/1930. Unique Length-3 Palindromic Subsequences1
new file mode 100644
index 0000000..c50ecc2
--- /dev/null
+++ b/1930. Unique Length-3 Palindromic Subsequences1	
@@ -0,0 +1,33 @@
+class Solution {
+public:
+    int countPalindromicSubsequence(string s) {
+        vector<string>subbstr;
+        vector<int>a(26, 0); 
+        int n = s.size();
+        for(int i = 0; i < n; i++){
+            if(a[s[i] - 'a'] == 0){
+                string sub = s.substr(i, n - i);
+                subbstr.push_back(sub);
+                a[s[i] - 'a'] = 1;
+            }
+        }
+        int res = 0;
+        for(int i = 0; i < subbstr.size(); i++){
+            a.clear();
+            a.resize(26, 0);
+            int j = subbstr[i].size() - 1;
+            while(j > 0 && subbstr[i][j] != subbstr[i][0]){
+                j--;
+            }
+            j -= 1;
+            while(j > 0 ){
+                if(a[subbstr[i][j] - 'a'] == 0){
+                    res++;
+                    a[subbstr[i][j] - 'a'] = 1;
+                }
+                j--;
+            }
+        }
+        return res;
+    }
+};