Added codechef question QUIZPLAG

Author: JahnaviKashyap19

Codechef solutions/QUIZPLAG.cpp

@@ -0,0 +1,43 @@
+// THIS QUESTION IS AVAILABLE ON CODECHEF https://www.codechef.com/problems/QUIZPLAG
+#include <iostream>
+#include<vector>
+#include<cstring>
+using namespace std;
+void solve()
+{
+    int n,m,k,id;
+    cin>>n>>m>>k;
+    int L[n+m+1];
+    memset(L,0,sizeof(L));
+    for(int i=1;i<=k;i++)
+    {
+        cin>>id;
+        L[id]++;
+    }
+    vector<int>ans;
+    for(int i=1;i<=n;i++)
+    {
+        if(L[i]>1)
+        {
+            ans.push_back(i);
+        }
+    }
+    int size=ans.size();
+    cout<<size;
+    for(int i=0;i<size;i++)
+    {
+        cout<<" "<<ans[i];
+    }
+    cout<<endl;
+    
+}
+
+int main() {
+	int t;
+	cin>>t;
+	while(t--)
+	{
+	    solve();
+	}
+	return 0;
+}