add API and data read

main.cpp

+#include <iostream>
+#include <vector>
+#include "sorting.h"
+using namespace std;
+
+int main(){
+
+	int n;
+	cin>>n;
+	vector<int> arr;
+	for (int i=0; i<n; i++){
+		int x;
+		cin>>x;
+		arr.push_back(x);
+	}
+
+	vector<int> a = sort_custom(arr);
+	for (int i=0;  i < a.size();  i++)
+    {
+        cout<<a[i]<<" ";
+    }
+}
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sorting.h

+#include <iostream>
+#include <vector>
+using namespace std;
+
+vector<int> sort_custom( vector<int> );
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