Added Merge Sort program in C++

merge-sort.cpp

@@ -0,0 +1,79 @@
+/*
+Program to sort the array using merge sort
+
+code by iamkakashi
+*/
+#include<bits/stdc++.h>
+using namespace std;
+void merge(int a[], int l, int m, int r)
+    {
+
+         int n=max(a[m],a[r])+1;
+         int i=l,j=m+1,k=l;
+         while(i<=m && j<=r && k<=r){
+             int e=a[i]%n;
+             int e1=a[j]%n;
+             if(e<=e1){
+                 a[k]+=e*n;
+                 k++;
+                 i++;
+             }
+             else{
+                 a[k]+=e1*n;
+                 k++;
+                 j++;
+             }
+         }
+         while(i<=m){
+             int e=a[i]%n;
+             a[k]+=e*n;
+             k++;
+             i++;
+         }
+         while(j<=r){
+             int e1=a[j]%n;
+             a[k]+=e1*n;
+             k++;
+             j++;
+         }
+         for(int i=l;i<=r;i++){
+             a[i]=a[i]/n;
+         }
+    }
+    void mergeSort(int a[], int l, int r)
+    {
+
+
+        if(l<r){
+            int mid=(l+r)/2;
+            mergeSort(a,l,mid);
+            mergeSort(a,mid+1,r);
+            merge(a,l,mid,r);
+        }
+    }
+
+void printArray(int arr[], int size)
+{
+    int i;
+    for (i=0; i < size; i++)
+        printf("%d ", arr[i]);
+    printf("\n");
+}
+
+
+int main()
+{
+    int n,i;
+    cout<<"Enter number of elements: ";
+    cin>>n;
+    int arr[n+1];
+    cout<<"Enter elements: ";
+    for(i=0;i<n;i++){
+      cin>>arr[i];
+    }
+    mergeSort(arr, 0, n-1);
+    cout<<"Sorted array is: ";
+    printArray(arr, n);
+
+    return 0;
+}