From 066cf1509793e881fd04f82665012303c58c9bca Mon Sep 17 00:00:00 2001
From: Shrey Gupta <75122294+Shreygupta2002@users.noreply.github.com>
Date: Sat, 7 Oct 2023 13:41:29 +0530
Subject: [PATCH] Added Quick Sort Algorithm

Please add the hacktoberfest tag.
---
 c++/quick_sort.cpp | 86 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)
 create mode 100644 c++/quick_sort.cpp

diff --git a/c++/quick_sort.cpp b/c++/quick_sort.cpp
new file mode 100644
index 0000000..2d87bac
--- /dev/null
+++ b/c++/quick_sort.cpp
@@ -0,0 +1,86 @@
+#include<bits/stdc++.h>
+using namespace std;
+typedef long long int ll;
+void swap(int*a,int*b)
+{
+	int t=*a;
+	*a=*b;
+	*b=t;
+}
+int partition(int a[], int l, int r)
+{
+	// Taking the last element as the pivot
+	int pivot=a[r];
+	
+	int pos=l-1;
+	for(int i=l;i<r;i++)
+	{
+		if(a[i]<=pivot)
+		{
+			pos++;
+			swap(&a[pos],&a[i]);
+		}
+	}
+	swap(&a[pos+1],&a[r]);
+	return pos+1;
+}
+int main()
+{
+    ios::sync_with_stdio(0);cin.tie(0);
+    mt19937 rng((unsigned int) chrono::steady_clock::now().time_since_epoch().count());
+    auto start=chrono::high_resolution_clock::now();
+    
+    //code here
+
+    // Taking Input
+    int n;
+    cin>>n;
+    int a[n];
+    for(int i=0;i<n;i++)
+    {
+    	cin>>a[i];
+    }
+
+
+    // Creating a stack
+    int stack[n];
+    int top=-1;
+
+    stack[++top]=0;
+    stack[++top]=n-1;
+
+    // While stack is not empty
+    while(top>=0)
+    {
+    	int r=stack[top--];
+    	int l=stack[top--];
+
+    	// Setting pivot element at its correct position in the sorted array
+    	int temp=partition(a,l,r);
+
+    	// Taking the elements on the left in the stack
+    	if(temp-1>l)
+    	{
+    		stack[++top]=l;
+    		stack[++top]=temp-1;
+    	}
+
+    	// Taking the elements on the right in the stack
+    	if(temp+1<r)
+    	{
+    		stack[++top]=temp+1;
+    		stack[++top]=r;
+    	}
+    }
+
+    // Printing the sorted array
+    for(int i=0;i<n;i++)
+    {
+    	cout<<a[i]<<" ";
+    }
+
+
+    auto stop=chrono::high_resolution_clock::now();
+    auto duration=chrono::duration_cast<chrono::microseconds>(stop-start);
+    cerr<<duration.count()/1000.0<<" ms\n";
+}
\ No newline at end of file