From 7d8a3621a585fbd1bf1decfbfe2e6af5ef81eb26 Mon Sep 17 00:00:00 2001
From: unknown <kamalaujla4vr@gmail.com>
Date: Mon, 13 Apr 2020 22:16:33 +0530
Subject: [PATCH] Quick sort and merge sort added

---
 Sorting Algorithms/merge-sort.cpp | 102 ++++++++++++++++++++++++++++++
 Sorting Algorithms/quick-sort.cpp |  72 +++++++++++++++++++++
 2 files changed, 174 insertions(+)
 create mode 100644 Sorting Algorithms/merge-sort.cpp
 create mode 100644 Sorting Algorithms/quick-sort.cpp

diff --git a/Sorting Algorithms/merge-sort.cpp b/Sorting Algorithms/merge-sort.cpp
new file mode 100644
index 0000000..40c304d
--- /dev/null
+++ b/Sorting Algorithms/merge-sort.cpp	
@@ -0,0 +1,102 @@
+#include<stdlib.h> 
+#include<stdio.h> 
+#include<iostream>
+using namespace std;
+  
+// Merges two subarrays of arr[]. 
+// First subarray is arr[l..m] 
+// Second subarray is arr[m+1..r] 
+void merge(int arr[], int l, int m, int r) 
+{ 
+    int i, j, k; 
+    int n1 = m - l + 1; 
+    int n2 =  r - m; 
+  
+    /* create temp arrays */
+    int L[n1], R[n2]; 
+  
+    /* Copy data to temp arrays L[] and R[] */
+    for (i = 0; i < n1; i++) 
+        L[i] = arr[l + i]; 
+    for (j = 0; j < n2; j++) 
+        R[j] = arr[m + 1+ j]; 
+  
+    /* Merge the temp arrays back into arr[l..r]*/
+    i = 0; // Initial index of first subarray 
+    j = 0; // Initial index of second subarray 
+    k = l; // Initial index of merged subarray 
+    while (i < n1 && j < n2) 
+    { 
+        if (L[i] <= R[j]) 
+        { 
+            arr[k] = L[i]; 
+            i++; 
+        } 
+        else
+        { 
+            arr[k] = R[j]; 
+            j++; 
+        } 
+        k++; 
+    } 
+
+    while (i < n1) 
+    { 
+        arr[k] = L[i]; 
+        i++; 
+        k++; 
+    } 
+  
+    while (j < n2) 
+    { 
+        arr[k] = R[j]; 
+        j++; 
+        k++; 
+    } 
+} 
+  
+
+void mergeSort(int arr[], int l, int r) 
+{ 
+    if (l < r) 
+    { 
+        int m = l+(r-l)/2;  
+        mergeSort(arr, l, m); 
+        mergeSort(arr, m+1, r); 
+  
+        merge(arr, l, m, r); 
+    } 
+} 
+  
+  
+void printArray(int A[], int size) 
+{ 
+    int i; 
+    for (i=0; i < size; i++) 
+        cout<<A[i]<<" "; 
+    cout<<endl; 
+} 
+  
+int main() 
+{ 
+    int arr[10];
+	int n;
+	cout<<"Enter the size of array: ";
+	cin>>n;
+	cout<<"Enter the elements: ";
+	
+	for(int i=0;i<n;i++){
+		cin>>arr[i];
+	}
+	 
+     
+  
+    cout<<"Given array is: "<<endl; 
+    printArray(arr, n); 
+  
+    mergeSort(arr, 0, n - 1); 
+  
+    cout<<endl<<"Sorted Array is: "<<endl; 
+    printArray(arr, n); 
+    return 0; 
+} 
diff --git a/Sorting Algorithms/quick-sort.cpp b/Sorting Algorithms/quick-sort.cpp
new file mode 100644
index 0000000..f308401
--- /dev/null
+++ b/Sorting Algorithms/quick-sort.cpp	
@@ -0,0 +1,72 @@
+#include <iostream> 
+using namespace std;  
+  
+
+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);  
+    }  
+}  
+  
+
+void display(int arr[], int size)  
+{  
+    int i;  
+    for (i = 0; i < size; i++)  
+        cout << arr[i] << " ";  
+    cout << endl;  
+}  
+  
+
+int main()  
+{  
+    int arr[10];  
+    int n;
+	cout<<"Enter the size of array: ";
+	cin>>n;  
+	cout<<"Enter the elements of array: ";
+	for(int i=0;i<n;i++){
+		cin>>arr[i];
+	}
+	cout<<"Enter the index of element you want to pivot: ";
+	int pivot;
+	cin>>pivot;
+	swap(&arr[pivot],&arr[n-1]);
+    quickSort(arr, 0, n - 1);  
+    cout << "Sorted array: \n";  
+    display(arr, n);  
+    return 0;  
+}