How to add score counter?

558fe5180e0e8fc922d31c23ef84d240

How to add score counter to rock paper scissors game? I can't get score counter work. (Player wins, Computerwins)
I got it working without functions but now when I added them I don't just get it how to do it...

#include <iostream>
#include <math.h>
#include <string>

int numGen ();
int choiceConverter (std :: string);
void DisplayComputer (int);
void winner (int, int);

int main ()   
{
std :: string playerChoose;
int player;
int compChoice;
int rounds = 0;
int gains = 0;
int machineGains = 0;

// Ask the user how many rounds to play? 
std :: cout << "How many rounds do you want to play?" << std :: endl;  
std :: cout << "Enter rounds>";
std :: cin >> rounds;

for (int round = 1; round <= rounds; round ++)
{

std :: cout << "Round number:" << round << "/" << rounds << std :: endl;

std :: cout << "\nSelect rock, paper or scissors:";
std :: cin >> playerChoose;
std :: cout << "\ nYour selection is:" << PlayerChoose << "\ n";



compChoice = numGen ();
player = choiceConverter (playerChoice);
displayComputer (compChoice);
winner (compChoice, player);
}

} 
int numGen ()
{
std :: srand (time (0));
int randomi = rand ()% 3 + 1;

return randomi;
}

int choiceConverter(std :: string player1) 
{
int numEquiv = 0;

if (player1 == "rock")
character code = 1;
else if (player1 == "paper")
character code = 2;
else if (player1 == "scissors")
character code = 3;    
return numEquiv
}
void displayComputer (int player2)
{
if (player2 == 1)
{
std :: cout << "The computer chose rock \ n";
}
else if (player2 == 2)
{
std :: cout << "The computer chose paper \ n";
    }
else if (player2 == 3)
{
std :: cout << "The computer chose scissors \ n";
}
}

void winner (int player1, int player2)
{

if ((player1 == 1 && player2 == 2) || (player1 == 2 && player2 == 3) || (player1 == 3 && player2 == 1))
{
std :: cout << "\nYou won the game! \ n \ n";

}
else if ((player1 == 1 && player2 == 3) || (player1 == 2 && player2 == 1) || (player1 == 3 && player2 == 2))
{
std :: cout << "\ nComputer won the game! \ n \ n";

}
else
{
std :: cout << "\nDraw \ n \ n";
}   
}