Create Substrings That Begin and End With the Same Letter.java

varunu28 · web-flow · commit b8a29e6a0855 · 2024-06-09T09:45:41.000-07:00
diff --git a/Medium/Substrings That Begin and End With the Same Letter.java b/Medium/Substrings That Begin and End With the Same Letter.java
@@ -0,0 +1,12 @@
+class Solution {
+    public long numberOfSubstrings(String s) {
+        int n = s.length();
+        long result = 0;
+        long[] prefixCount = new long[26];
+        for (int i = 0; i < n; i++) {
+            prefixCount[s.charAt(i) - 'a']++;
+            result += prefixCount[s.charAt(i) - 'a'];
+        }
+        return result;
+    }
+}
