5-10 Game update

#include <bits/stdc++.h>
using namespace std;

void menu()
{
    system("cls");
}

int main()
{
    cout << "Welcome to 5-10 game!" << endl << "In this game, you can add 5 or 10 to the previous number."<<endl<<"Your target is to reach 100 first. The game always starts with 0."<<endl<<"For example, if you are provided with 50, in this case you can jump to 55 or 60. From 15, you can jump to 20 or 25."<<endl<<"Hope you enjoy the game! Best of luck"<<endl<<endl;
    int game;
    cout << "Press 1 to enter the game : ";
    cin >> game;
    menu();
    cout << "Press 1 for single player / ";
    cout << "Press 2 for multiplayers : ";
    int game_players;
    cin >> game_players;
    menu();
    if(game_players == 1)
    {
        cout << "Open first? Y/N : ";
        char opening;
        cin >> opening;
        menu();
        if(opening=='Y')
        {
            int x,y=0;
            while(1)
            {
                cout<<"You: ";
                cin >> x;
                if(x==y+5 || x==y+10)
                {
                    if(x==5)
                    {
                        y=10;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==10)
                    {
                        y=15;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==15)
                    {
                        y=20;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==20)
                    {
                        y=30;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==25)
                    {
                        y=30;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==30)
                    {
                        y=40;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==35)
                    {
                        y=40;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==40)
                    {
                        y=45;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==45)
                    {
                        y=55;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==50)
                    {
                        y=55;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==55)
                    {
                        y=60;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==60)
                    {
                        y=70;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==65)
                    {
                        y=70;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==70)
                    {
                        y=75;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==75)
                    {
                        y=85;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==80)
                    {
                        y=85;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==85)
                    {
                        y=90;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==90)
                    {
                        y=100;
                        cout<<"CPU: "<<y<<endl;
                        cout<<"Sorry! You lose"<<endl;
                        cout<<"Press 0 to exit the game ";
                        int exit;
                        cin>>exit;
                        if(exit==0) return 0;
                    }
                    if(x==95)
                    {
                        y=100;
                        cout<<"CPU: "<<y<<endl;
                        cout<<"Sorry! You lose"<<endl;
                        cout<<"Press 0 to exit the game ";
                        int exit;
                        cin>>exit;
                        if(exit==0) return 0;
                    }
                    if(x==100)
                    {
                        cout<<"Congratulations! You win"<<endl;
                        cout<<"Press 0 to exit the game ";
                        int exit;
                        cin>>exit;
                        if(exit==0) return 0;
                    }
                }
                else
                {
                    cout << "Wrong Input. Bye"<<endl;
                    cout<<"Press 0 to exit the game ";
                        int exit;
                        cin>>exit;
                        if(exit==0) return 0;
                }
            }
        }
        else
        {
            int x,y=10;
            cout<<"CPU: "<<y<<endl;
            while(1)
            {
                cout<<"You: ";
                cin>>x;
                if(x==y+5 || x==y+10)
                {
                    if(x==15)
                    {
                        y=20;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==20)
                    {
                        y=30;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==25)
                    {
                        y=30;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==30)
                    {
                        y=40;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==35)
                    {
                        y=40;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==40)
                    {
                        y=45;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==45)
                    {
                        y=55;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==50)
                    {
                        y=55;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==55)
                    {
                        y=60;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==60)
                    {
                        y=70;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==65)
                    {
                        y=70;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==70)
                    {
                        y=75;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==75)
                    {
                        y=85;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==80)
                    {
                        y=85;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==85)
                    {
                        y=90;
                        cout<<"CPU: "<<y<<endl;
                    }
                    if(x==90)
                    {
                        y=100;
                        cout<<"CPU: "<<y<<endl;
                        cout<<"Sorry! You lose"<<endl;
                        cout<<"Press 0 to exit the game ";
                        int exit;
                        cin>>exit;
                        if(exit==0) return 0;
                    }
                    if(x==95)
                    {
                        y=100;
                        cout<<"CPU: "<<y<<endl;
                        cout<<"Sorry! You lose"<<endl;
                        cout<<"Press 0 to exit the game ";
                        int exit;
                        cin>>exit;
                        if(exit==0) return 0;
                    }
                    if(x==100)
                    {
                        cout<<"Congratulations! You win"<<endl;
                        cout<<"Press 0 to exit the game ";
                        int exit;
                        cin>>exit;
                        if(exit==0) return 0;
                    }
                }
                else
                {
                    cout << "Wrong Input. Bye"<<endl;
                    cout<<"Press 0 to exit the game ";
                        int exit;
                        cin>>exit;
                        if(exit==0) return 0;
                }
            }
        }
    }
    else
    {
        char player1[100],player2[100];
        cout<<"Enter the first name of player 1 : ";
        scanf("%s",player1);
        cout<<"Enter the first name of player 2 : ";
        scanf("%s",player2);
        int x=0,y=0;
        printf("Who want to move first? Player 1(Press 1) or Player 2(Press 2) : ");
        int first_move;
        cin >> first_move;
        menu();
        for(int i=1 ; ; i++)
        {
            if(i%2!=0 && first_move==1)
            {
                printf("turn of %s : ",player1);
                cin>>x;
                if(x==y+5 || x==y+10)
                {
                    if(x==100)
                    {
                        printf("%s wins\n",player1);
                        cout<<"Press 0 to exit the game ";
                        int exit;
                        cin>>exit;
                        if(exit==0) return 0;
                    }
                }
                else
                {
                    cout << "Wrong Input. Bye"<<endl;
                    cout<<"Press 0 to exit the game ";
                        int exit;
                        cin>>exit;
                        if(exit==0) return 0;
                }
            }
            else if(i%2==0 && first_move==1)
            {
                printf("turn of %s : ",player2);
                cin>>y;
                if(y==x+5 || y==x+10)
                {
                    if(y==100)
                    {
                        printf("%s wins\n",player2);
                        cout<<"Press 0 to exit the game ";
                        int exit;
                        cin>>exit;
                        if(exit==0) return 0;
                    }
                }
                else
                {
                    cout << "Wrong Input. Bye"<<endl;
                    cout<<"Press 0 to exit the game ";
                        int exit;
                        cin>>exit;
                        if(exit==0) return 0;
                }
            }
            if(i%2!=0 && first_move==2)
            {
                printf("turn of %s : ",player2);
                cin>>x;
                if(x==y+5 || x==y+10)
                {
                    if(x==100)
                    {
                        printf("%s wins\n",player2);
                        cout<<"Press 0 to exit the game ";
                        int exit;
                        cin>>exit;
                        if(exit==0) return 0;
                    }
                }
                else
                {
                    cout << "Wong Input. Bye"<<endl;
                    cout<<"Press 0 to exit the game ";
                        int exit;
                        cin>>exit;
                        if(exit==0) return 0;
                }
            }
            else if(i%2==0 && first_move==2)
            {
                printf("turn of %s : ",player1);
                cin>>y;
                if(y==x+5 || y==x+10)
                {
                    if(y==100)
                    {
                        printf("%s wins\n",player1);
                        cout<<"Press 0 to exit the game ";
                        int exit;
                        cin>>exit;
                        if(exit==0) return 0;
                    }
                }
                else {
                    cout << "Wrong Input. Bye"<<endl;
                    cout<<"Press 0 to exit the game ";
                        int exit;
                        cin>>exit;
                        if(exit==0) return 0;
                }
            }
        }
    }
    return 0;
}