sukodu

hi
i am a new member so please excuse me i any mistakes
i am doing an sukodu solving prg
uptil now i have done this:::

Code:

#include<iostream.h>
#include<conio.h>
#include<stdlib.h>
#include<dos.h>
int mat[20][20];
int t,j;

void main()
{
	clrscr();
	cout<<"Well come...to SUKODU";
	delay(2000);

	clrscr();
	for(int i=1;i<=9;i++)
	 {
		cout<<"\n";
		 for(j=1;j<=9;j++)
		  {
			mat[i][j]=  rand()%9+1;
			cout<<mat[i][j];

			 if(j==3||j==6)
			cout<<"  ";
			if(i==6&&j==9||i==3&&j==9)
			{
			cout<<"\n";
			continue;
			}
		   }
	    cout<<"\n";
	 }
getch();
}

i am getting a formatted output::
553 228 188

556 827 241

913 599 364


428 155 599

291 143 977

461 927 222


749 828 151

784 379 592

929 693 867



now please help me to remove the duplicates.in rows and columns..

thank u