From da2f781c3998e74aa3d62af32f314096d2acf132 Mon Sep 17 00:00:00 2001
From: abster12 <abhigyan0987@gmail.com>
Date: Mon, 23 Oct 2017 19:20:55 +0530
Subject: [PATCH] Create quicksort.cpp

---
 quicksort.cpp | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)
 create mode 100644 quicksort.cpp

diff --git a/quicksort.cpp b/quicksort.cpp
new file mode 100644
index 0000000..1805a93
--- /dev/null
+++ b/quicksort.cpp
@@ -0,0 +1,68 @@
+#include <iostream>
+ 
+using namespace std;
+ 
+void quick_sort(int[],int,int);
+int partition(int[],int,int);
+ 
+int main()
+{
+    int a[50],n,i;
+    cout<<"How many elements?";
+    cin>>n;
+    cout<<"\nEnter array elements:";
+    
+    for(i=0;i<n;i++)
+        cin>>a[i];
+        
+    quick_sort(a,0,n-1);
+    cout<<"\nArray after sorting:";
+    
+    for(i=0;i<n;i++)
+        cout<<a[i]<<" ";
+    
+    return 0;        
+}
+ 
+void quick_sort(int a[],int l,int u)
+{
+    int j;
+    if(l<u)
+    {
+        j=partition(a,l,u);
+        quick_sort(a,l,j-1);
+        quick_sort(a,j+1,u);
+    }
+}
+ 
+int partition(int a[],int l,int u)
+{
+    int v,i,j,temp;
+    v=a[l];
+    i=l;
+    j=u+1;
+    
+    do
+    {
+        do
+            i++;
+            
+        while(a[i]<v&&i<=u);
+        
+        do
+            j--;
+        while(v<a[j]);
+        
+        if(i<j)
+        {
+            temp=a[i];
+            a[i]=a[j];
+            a[j]=temp;
+        }
+    }while(i<j);
+    
+    a[l]=a[j];
+    a[j]=v;
+    
+    return(j);
+}