Memory game

[gsn21]

It is a program for a normal memory matching game. I had to refer online to make it. It is not working and I don't know where I have gone wrong. For the first couple of user inputs it is working but after the the third inout the cout statement is presented multiple times. I have checked the loops as well. It would be a great help if someone could look at it with a fresh eye and point out where I am going wrong.
#include <iostream.h>
#include <stdlib.h>
#include <time.h>
void shuffle(int [4][4]);

int main()
{
char comma, ans = 'y';
int r1, c1, r2, c2, cards[4][4], i(0);
char cardstatus[4][4]; // array to store whether card is flipped or not, you can use char if bool doesn't work for you.
char gameover = 0; // if bool doesn't work for you, use char in same way I told for cardstatus.
int moves;
do
{
moves = 0;
//shuffle
shuffle(cards); // I think shuffling cards is better idea than shuffling base start array.
//display board
cout<<" 1 2 3 4\n";
cout<<" ";
for (int i=0; i<=8; i++)
{
cout<<"-";
}
cout<<endl;
for (int r=0; r<4; r++)
{
cout<<r+1<<" | ";
for (int c=0; c<4; c++)
{
cout<<"* ";
cardstatus[r][c] = 0; // use 0 for 0 and 1 for 1 if 1/0 is not supported.
}
cout<<endl;
}
cout<<endl;
do // game starts from here as user will do moves here onwards.
{
do
{
//selection
cout<<"Please insert the first card row and column separated by a comma.\n";
cin>>r1>>comma>>c1;
if(cardstatus[r1-1][c1-1] == 1) // check if the card is flipped.
{
cout << "This card is already flipped! Select another card.";
}
}while(cardstatus[r1-1][c1-1]!= 0);
do
{
cout<<"Please insert the second card row and column separated by a comma.\n";
cin>>r2>>comma>>c2;
if(cardstatus[r2-1][c2-1] == 1) // check if the card is flipped.
{
cout << "This card is already flipped! Select another card.";
}
if((r1==r2)&&(c1==c2))
{
cout << "You can't select same card twice!";
continue;
}
}while(cardstatus[r2-1][c2-1]!= 0);
//fix
r1--;
c1--;
r2--;
c2--;
//reveal
cout<<" 1 2 3 4\n";
cout<<" ";
for (int i=0; i<=8; i++)
{
cout<<"-";
}
cout<<endl;
for (int r=0; r<4; r++)
{
cout<<r+1<<" | ";
for (int c=0; c<4; c++)
{
if ((r==r1)&&(c==c1))
{
cout<<cards[r][c]<<" ";
}
else if((r==r2)&&(c==c2))
{
cout<<cards[r][c]<<" ";
}
else if (cardstatus[r][c] == 1)
{
cout<<cards[r][c]<<" ";
}
else
{
cout<<"* ";
}
}
cout<<endl;
}
//match?
if (cards[r1][c1]==cards[r2][c2]) // if cards match, keep them flipped.
{
cout << "Cards Matched!"<<endl;

cardstatus[r1][c1] = 1;
cardstatus[r2][c2] = 1;
}
cin.get();
cin.get();
//this pushes the next board onto a blank screen
for (int b=0; b<=20; b++)
cout<<endl;
for (int p=0; p<4; p++) // reprint the board, makes it easy for user to put a new guess.
{
cout<<p+1<<" | ";
for (int c=0; c<4; c++)
{
if (cardstatus[r][c] == 1)
{
cout<<cards[r][c]<<" ";
}
else
{
cout<<"* ";
}
}
cout<<endl;
}
gameover = 1;
for (int r=0; r<4; r++) // check all card status, they all should be 1/flipped to end the game.
{
for (int c=0; c<4; c++)
{
if(cardstatus[r][c]==0)
{
gameover = 0;
break;
}
}
if(gameover == 0)
{
break;
}
}
moves++; // counting moves here.
//repeat
}while(gameover != 1); // loop, the only way to get out is to finish the game!
cout << "Congratulations, You won!!!"<<endl;
cout << "It Required " << moves << " moves to finish it."<<endl<<endl;
cout << "Would you like to play again? (y=Yes/n=No) : ";
ans = cin.get();
}while(ans == 'y' || ans == 'Y'); // If user wants to play game again.
cin.get();
return 0;
}
void shuffle(int cards[][4])
{
int start[16]={1,2,3,4,5,6,7,8,1,2,3,4,5,6,7,8};
for (int s=0; s<=20; s++)
{
for (int x=0; x<16; x++)
{
srand((unsigned)time(NULL));
int i=rand()%15+1;
int temp=start[x];
start[x]=start[i];
start[i]=temp;
}
}
int i=0;
for (int r=0; r<4; r++) // put values in cards here
{
for (int c=0; c<4; c++)
{
cards[r][c]=start[i];
cout<<cards[r][c];
i=i+1;
}
cout<<endl;
}
}