Class Maincodes

CommonMatrixElements.java:48–113

// second approach (without data structure)
import java.util.*;
class Maincodes
{
  public static void main(String args[])
  {
    // Input
    int mat[][] =
   {
       {1, 2, 1, 4, 8},
       {8, 7, 8, 5, 1},
       {8, 7, 7, 3, 1},
       {8, 1, 1, 7, 9},
   };
   // Funtion call
   commonElements(mat,mat.length,mat[0].length);
  }
  // function to check if there is any duplicate elements in the firstRow
  public static boolean seen(int arr[],int element,int end)
  {
    for(int i=0;i<end;i++)
    {
      if(element==arr[i]) return true;
    }
    return false;
  }
  public static void commonElements(int Mat[][], int r, int c)
  {
    // pick one by one element of the first row and check if they are present in all rows.
    for(int firstRow=0;firstRow<c;firstRow++)
    {
      // pick element
      int element=Mat[0][firstRow];
      // if duplicate then skip the element
      if(seen(Mat[0],element,firstRow)) continue;
      // variable for tracking rows.
      int count=0;
      // if element is not present in anyone of the row then skip the element.
      int flag=0;
      // traverse from 1st to last row
      for(int row=1;row<r;row++)
      {
        for(int col=0;col<c;col++)
        {
          // if element is found then increment the counter
          if(element==Mat[row][col])
          {
            count++;
            // if present in last row and count is equal to row-1, then print it
            if(row==r-1 && count==r-1)
              System.out.println(element);
              // if count is same as row then break to avoid adding duplicates
            else if(row!=r-1 && count==row)
              break;
              // if element not present in the current row then set flag to 1,
            else
            {
              flag=1;
              break;
            }