Sorted out the missing file warning and added code for Pell Numbers

C++/Sorting algo/quicksort.cpp

@@ -1,42 +1,67 @@
-// A utility function to swap two elements  
-void swap(int* a, int* b)  
-{  
-    int t = *a;  
-    *a = *b;  
-    *b = t;  
-}  
-int partition (int arr[], int low, int high)  
-{  
-    int pivot = arr[high]; // pivot  
-    int i = (low - 1); // Index of smaller element  
-
-    for (int j = low; j <= high - 1; j++)  
-    {  
-        // If current element is smaller than the pivot  
-        if (arr[j] < pivot)  
-        {  
-            i++; // increment index of smaller element  
-            swap(&arr[i], &arr[j]);  
-        }  
-    }  
-    swap(&arr[i + 1], &arr[high]);  
-    return (i + 1);  
-}  
-
- void quickSort(int arr[], int low, int high)  
-{  
-    if (low < high)  
-    {  
-        int pi = partition(arr, low, high);   
-       quickSort(arr, low, pi - 1);  
-       quickSort(arr, pi + 1, high);  
-   }  
-}  
-/* Function to print an array */
-void printArray(int arr[], int size)  
-{  
-    int i;  
-    for (i = 0; i < size; i++)  
-        cout << arr[i] << " ";  
-    cout << endl;  
-}   
+#include <iostream>
+#include<vector>
+#include<algorithm>
+#include<utility>
+#include<set>
+#include<map>
+#include<unordered_map>
+using namespace std;
+
+
+
+int partition (int arr[], int low, int high) 
+{ 
+	int pivot = arr[high]; // pivot 
+	int i = (low - 1); // Index of smaller element 
+
+	for (int j = low; j <= high- 1; j++) 
+	{ 
+		// If current element is smaller than or 
+		// equal to pivot 
+		if (arr[j] <= pivot) 
+		{ 
+			i++; // increment index of smaller element 
+			swap(arr[i], arr[j]); 
+		} 
+	} 
+	swap(arr[i + 1], arr[high]); 
+	return (i + 1); 
+} 
+
+
+void quickSort(int arr[], int low, int high) 
+{ 
+	if (low < high) 
+	{ 
+		/* pi is partitioning index, arr[p] is now 
+		at right place */
+		int pi = partition(arr, low, high); 
+
+		// Separately sort elements before 
+		// partition and after partition 
+		quickSort(arr, low, pi - 1); 
+		quickSort(arr, pi + 1, high); 
+	} 
+} 
+
+
+void printArray(int arr[], int size) 
+{ 
+	int i; 
+	for (i=0; i < size; i++) 
+		cout<<arr[i]<<" "; 
+	cout<<endl;
+} 
+
+int main() 
+{ 
+	int arr[] = {10, 7, 8, 9, 1, 5}; 
+	int n = sizeof(arr)/sizeof(arr[0]); 
+
+	cout<<"Unsorted array:"<<"\n"; 
+	printArray(arr, n); 
+	quickSort(arr, 0, n-1); 
+	cout<<"Sorted array:"<<"\n"; 
+	printArray(arr, n); 
+	return 0; 
+} 

Java/pell.java

@@ -0,0 +1,21 @@
+import java.io.*;
+import java.util.*;
+
+class pell{
+
+    public static void main(String args[])
+    {
+    Scanner sc = new Scanner(System.in);    
+    //User input of the number of pell numbers
+    int n = sc.nextInt();
+    int a=1,b=0,c,i;
+    System.out.println("First "+n+" Pell numbers are: ");
+    for(i=1; i<=n; i++)
+     {
+      c= a + 2*b;
+      System.out.print(c+" ");
+      a = b;
+      b = c;
+     }
+   }
+}