From faa5a54708682ce201e9481b785a90c7c82b784d Mon Sep 17 00:00:00 2001
From: som <som@som-Inspiron-5567>
Date: Sat, 19 Oct 2019 00:50:16 +0530
Subject: [PATCH] code for mergesort

---
 Day 22 mergesort.cpp | 73 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100644 Day 22 mergesort.cpp

diff --git a/Day 22 mergesort.cpp b/Day 22 mergesort.cpp
new file mode 100644
index 0000000..ed8f46c
--- /dev/null
+++ b/Day 22 mergesort.cpp	
@@ -0,0 +1,73 @@
+#include<iostream>
+using namespace std;
+int merge(int L[],int R[],int A[],int l,int r)
+{
+
+//cout<<"l is"<<l<<endl;
+
+  int i=0,j=0,k=0;
+  while(i<l&&j<r)
+  {
+    if(L[i]<=R[j])
+            {
+              A[k]=L[i];
+              i++;
+            }
+    else
+            {
+              A[k]=R[j];
+              j++;
+            }
+    k++;
+  }
+    while(i<l)
+     {
+        A[k]=L[i];
+        i++;k++;
+     }
+      while(j<r)
+      {
+        A[k]=R[j];
+        j++;k++;
+      }
+}
+int mergesort(int A[],int n)
+{
+  //cout<<"n is "<<n<<endl;
+  if(n>=2){
+
+
+  int i;
+  int mid=n/2;
+  int L[mid];
+  int R[n-mid];
+
+  for(i=0;i<mid;i++)
+          L[i]=A[i];
+  for(i=mid;i<n;i++)
+          R[i-mid]=A[i];
+  int l= sizeof(L)/sizeof(L[0]);
+  int r= sizeof(R)/sizeof(R[0]);
+  mergesort(L,l);
+  mergesort(R,r);
+  merge(L,R,A,l,r);
+}
+}
+
+int main()
+{
+  int m,i;
+  cin>>m;
+  int A[m];
+  for(i=0;i<m;i++)
+{
+
+    cin>>A[i];
+
+}
+mergesort(A,m);
+for(i=0;i<m;i++)
+{
+  cout<<A[i]<<"\t"<<endl;
+}
+}