TicTacToe with win detection

#include <iostream>
using namespace std;
int x, y, c, i;
int board[3][3]={{0, 0, 0}, {0, 0, 0}, {0, 0, 0}};
int display(){
    system("cls");
    for(y = 0; y <= 2; y++){
        for(x = 0; x <= 2; x++){
            switch(board[y][x]){
                case 0: cout << "[_]";
                        break;
                case 1: cout << "[X]";
                        break;
                case 2: cout << "[O]";
                        break;
                default:cout << "[!]";
            }
        }cout << endl;
    }return 0;
}
int player1(){ //[X]
    cout << "[P1] Enter Y coordinate: ";
    cin >> y;
    cout << "[P1] Enter X coordinate: ";
    cin >> x;
    if(board[y][x] == 0){ board[y][x] = 1; }
    display();
    return 0;
}
int player2(){ //[O]
    cout << "[P2] Enter Y coordinate: ";
    cin >> y;
    cout << "[P2] Enter X coordinate: ";
    cin >> x;
    if(board[y][x] == 0){ board[y][x] = 2; }
    display();
    return 0;
}
int win(){
    for(i = 1; i <= 2; i++){
        for(x = 0; x <= 2; x++){
            if(board[0][x] == i && board[1][x] == i && board[2][x] == i){
                cout << "P" << i << " won!" << endl;
                exit;
            }
        }for(x = 0; x <= 2; x++){
            if(board[x][0] == i && board[x][1] == i && board[x][2] == i){
                cout << "P" << i << " won!" << endl;
                exit;
            }
        }if(board[0][0] == i && board[1][1] == i && board[2][2] == i){
                cout << "P" << i << " won!" << endl;
                exit;
        }if(board[2][0] == i && board[1][1] == i && board[0][2] == i){
                cout << "P" << i << " won!" << endl;
                exit;
        }
    }return 0;
}

int main() {
    display();
    player1();
    for(c = 0; c <= 3; c++){
        player2();
        win();
        player1();
        win();
    }return 0;
}