C# program to find common elements in three sorted arrays

Firstly, initialize three sorted arrays −

int []one = {20, 35, 57, 70}; int []two = {9, 35, 57, 70, 92}; int []three = {25, 35, 55, 57, 67, 70};

To find common elements in the three-sorted arrays, iterate through the arrays using a while loop and check the first array with a second and second array with the third −

while (i < one.Length &amp;&amp; j < two.Length &amp;&amp; k < three.Length) {    if (one[i] == two[j] &amp;&amp; two[j] == three[k]) {       Console.Write(one[i] + " ");       i++;j++;k++;    }    else if (one[i] < two[j])       i++;    else if (two[j] < three[k])       j++;    else       k++; }

Example

You can try to run the following code to find common elements in three sorted arrays.

Live Demo

using System; class Demo {    static void commonElements(int []one, int []two, int []three) {       int i = 0, j = 0, k = 0;       while (i < one.Length &amp;&amp; j < two.Length &amp;&amp; k < three.Length) {          if (one[i] == two[j] &amp;&amp; two[j] == three[k]) {             Console.Write(one[i] + " ");             i++;j++;k++;          }          else if (one[i] < two[j])             i++;          else if (two[j] < three[k])             j++;          else             k++;       }    }    public static void Main() {       int []one = {20, 35, 57, 70};       int []two = {9, 35, 57, 70, 92};       int []three = {25, 35, 55, 57, 67, 70};       Console.Write("Common elements: ");       commonElements(one, two, three);    } }

Output

Common elements: 35 57 70