cleanup

src/content/config.ts

@@ -12,6 +12,17 @@ const postsCollection = defineCollection({
   }),
 });
 
+const gistsCollection = defineCollection({
+  type: "content",
+  schema: z.object({
+    title: z.string(),
+    description: z.string().optional(),
+    date: z.string().optional(),
+  }),
+});
+
 export const collections = {
   posts: postsCollection,
+  gists: gistsCollection,
 };
+

src/content/gists/countGoodNumbers.mdx

@@ -0,0 +1,24 @@
+---
+title: "countGoodNumbers.cpp"
+date: "07/10/2025"
+---
+
+```cpp
+class Solution {
+public:
+    static constexpr long long MOD = 1e9 + 7;
+    long long mpow(long long a, long long b, long long mod=MOD) {
+        long long ans = 1;
+        while (b > 0) {
+            if (b & 1) ans = (ans * a) % MOD;
+            a = (a * a) % MOD;
+            b >>= 1;
+        }
+        return ans;
+    }
+    int countGoodNumbers(long long n) {
+        long long even = (n + 1) / 2, odd = n / 2;
+        return (mpow(5, even) * mpow(4, odd)) % MOD;
+    }
+};
+```