diff --git a/.DS_Store b/.DS_Store
index 39daaec68..50e1f7cb6 100644
Binary files a/.DS_Store and b/.DS_Store differ
diff --git a/Buzz_number.cpp b/Buzz_number.cpp
new file mode 100644
index 000000000..3d39c50f6
--- /dev/null
+++ b/Buzz_number.cpp
@@ -0,0 +1,17 @@
+//A buzz number is a number that is either divisble by 7 or has last digit as 7.
+#include <iostream>
+using namespace std;
+int main()
+{
+  int n,t;
+  cin >> t;
+  while(t--)
+  {
+   cin >> n;
+   if((n%7==0)||(n%10==7))
+    cout << n << " is a buzz number" << endl;
+   else
+    cout << n << " is not a buzz number" << endl;
+  }
+  return 0;
+}
diff --git a/Happy_number.cpp b/Happy_number.cpp
new file mode 100644
index 000000000..ca252bd6e
--- /dev/null
+++ b/Happy_number.cpp
@@ -0,0 +1,26 @@
+/* A happy number is a number whose sum of digits is calculated until the sum is a single digit,
+  and this sum turns out to be 1 */
+#include <iostream>
+using namespace std;
+int main()
+{
+  int n,k,s=0,d;
+  cout << "Enter a number:";
+  cin >> n;
+  s=n;k=n;
+  while(k>9)
+  {
+    while(k!=0)
+    {
+      d=n%10;
+      s+=d;
+      n/=10;
+    }
+    k=s;
+    s=0;
+  }
+  if(k==1)
+   cout << n << " is a happy number" << endl;
+  else
+   cout << n << " is not a happy number" << endl;
+}
diff --git a/Intersection_of_2_arrays.cpp b/Intersection_of_2_arrays.cpp
new file mode 100644
index 000000000..e2c064e1b
--- /dev/null
+++ b/Intersection_of_2_arrays.cpp
@@ -0,0 +1,30 @@
+#include <iostream>
+int main()
+{
+  int i,j,m,n;
+  cout <<"Enter size of array 1:";
+  cin >> m;
+  cout <<"Enter size of array 2:";
+  cin >> n;
+  int a[m];
+  int b[n];
+  cout <<"Enter elements of array 1:";
+  for(i=0;i<m;i++)
+   cin >> a[i];
+  for(i=0;i<n;i++)
+   cin >> b[i];
+  i=0;j=0;
+  while((i<m)&&(j<n))
+  {
+    if(a[i]<b[j])
+     i++;
+    else if(a[i]>b[j])
+     j++;
+    else
+    {
+      cout << a[i++]<<" ";
+      j++;
+    }
+  }
+  return 0;
+}
diff --git a/Union_of_2_arrays.cpp b/Union_of_2_arrays.cpp
new file mode 100644
index 000000000..4046e1ae8
--- /dev/null
+++ b/Union_of_2_arrays.cpp
@@ -0,0 +1,33 @@
+#include <iostream>
+int main()
+{
+   int m,n,i=0,j=0;
+   cout << "Enter size of both arrays:";
+   cin >> m >> n;
+   int a[m];
+   int b[n];
+   cout << "Enter elements of array 1:";
+   for(i=0;i<m;i++)
+    cin >>a[i];
+   cout << "Enter elements of array 2:";
+   for(i=0;i<n;i++)
+    cin >> b[i];
+  i=0;j=0;
+   while((i<m)&&(j<n))
+   {
+     if(a[i]<b[j])
+      cout << a[i++] <<" ";
+     else if(a[i]>b[j])
+      cout << b[j++] <<" ";
+    else
+    {
+      cout << a[i++];
+      j++;
+    }
+   }
+   while(i<m)
+    cout<< a[i++] <<" ";
+   while(j<n)
+    cout<< b[j++]<<" ";
+   return 0;
+}