feat: easy day 19 solution

easy/day_19/solution.cpp

@@ -1 +1,18 @@
-//write your code here
+#include <bits/stdc++.h>
+using namespace std;
+int main()
+{
+    int t;
+    cin >> t;
+    while (t--)
+    {
+        int n;
+        cin >> n;
+        cout << n << endl;
+        for (int i = 1; i <= n; i++)
+        {
+            cout << i << " ";
+        }
+        cout << endl;
+    }
+}