diff --git a/Armstrong number.c b/Armstrong number.c
new file mode 100644
index 0000000..00caa46
--- /dev/null
+++ b/Armstrong number.c	
@@ -0,0 +1,52 @@
+#include <stdio.h>
+#include<math.h>
+
+int check_armstrong(int);
+
+int main()
+{
+    int num_1,num_2;
+    printf("Enter first number : ");           
+    scanf("%d",&num_1);
+    printf("Enter second number : ");
+    scanf("%d",&num_2);
+    printf("\nThe armstrong numbers in the interval %d to %d are as follows: \n",num_1,num_2);
+    for(int i=num_1;i<=num_2;i++)
+    {
+        if(check_armstrong(i)==1)                 
+        {                                //checking whether the num is armstrong or
+            printf("%d\n",i);            //if it is then printing its value.
+        }
+    }
+    
+}
+
+int check_armstrong(int p)
+{
+    int temp,flag;                          
+    temp=p;
+    flag=p;
+    int rem=0,total=0,count=0;
+    while(p)                    //this while loop is for counting the total number of digits in the number
+    {
+        rem=p%10;
+        p=p/10;
+        count++;
+    }
+    rem=0;
+    while(temp)                        //this while loop is for calculating the sum of digits raised to the total 
+    {                                  //count of digits in the number as power
+       rem=temp%10;
+       total+=pow(rem,count);
+       temp=temp/10;
+    }
+    if(total==flag)
+    {
+        return 1;
+    }
+    else
+    {
+        return 0;
+    }
+    return 0;
+}
diff --git a/Operation on arrays.c b/Operation on arrays.c
new file mode 100644
index 0000000..0939408
--- /dev/null
+++ b/Operation on arrays.c	
@@ -0,0 +1,88 @@
+//Find the Union and Intersection of two sorted arrays.
+#include <stdio.h>
+
+void operations_on_array(int arr1[],int arr2[],int m,int n);
+
+int main()
+{
+    printf("Implementing union and intersection of two sorted arrays: \n");
+    int m,n;
+    printf("Enter the size of first array : ");
+    scanf("%d",&m);
+    printf("Enter the elememts of first array (in sorted manner): \n");
+    int arr1[m];
+    for(int i=0;i<m;i++)
+    {
+        scanf("%d",&arr1[i]);
+    }
+    printf("Enter the size of second array : ");
+    scanf("%d",&n);
+    printf("Enter the elememts of second array (in sorted manner): \n");
+    int arr2[n];
+    for(int i=0;i<n;i++)
+    {
+        scanf("%d",&arr2[i]);
+    }
+    
+    printf("The arrays are as follows: \n");
+    printf("Array 1: \n");
+    for(int i=0;i<m;i++)
+    {
+        printf("%d ",arr1[i]);
+    }
+    printf("\n");
+    printf("Array 2: \n");
+    for(int i=0;i<n;i++)
+    {
+        printf("%d ",arr2[i]);
+    }
+    
+    operations_on_array(arr1,arr2,m,n);
+    
+    return 0;
+}
+
+void operations_on_array(int arr1[],int arr2[],int m,int n){
+    printf("\nIntersection : ");
+    for(int i=0;i<m;i++)
+    {
+        for(int j=0;j<n;j++)
+        {
+            if(arr1[i]==arr2[j])
+            {
+                printf("%d ",arr1[i]);
+            }
+        }
+    }
+    printf("\nUnion : ");
+    int i=0,j=0;
+    while(i<m,j<n)
+    {
+        if(arr1[i]<arr2[j])
+        {
+            printf("%d ",arr1[i]);
+            i++;
+        }
+        else if(arr1[i]>arr2[j])
+        {
+            printf("%d ",arr2[j]);
+            j++;
+        }
+        else if(arr1[i]==arr2[j])
+        {
+            printf("%d ",arr1[i]);
+            i++;
+            j++;
+        }
+    }
+    while(i<m)
+    {
+          printf("%d ",arr1[i]);
+          i++;
+    }
+    while(j<n)
+    {
+         printf("%d ",arr2[j]);
+         j++;
+    }
+}