5-10 Game

#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 a specific number."<<endl<<"Your target is to reach 100 first. The game always starts with 0."<<endl<<"For example, you are provided with 50, in this case you can jump to 55 or 60."<<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;
           while(1) {
            cin >> x;
            if(x==5) {
                y=10;
                cout<<y<<endl;
            }
            if(x==10) {
                y=15;
                cout<<y<<endl;
            }
            if(x==15) {
                y=20;
                cout<<y<<endl;
            }
            if(x==20) {
                y=30;
                cout<<y<<endl;
            }
            if(x==25) {
                y=30;
                cout<<y<<endl;
            }
            if(x==30) {
                y=40;
                cout<<y<<endl;
            }
            if(x==35) {
                y=40;
                cout<<y<<endl;
            }
            if(x==40) {
                y=45;
                cout<<y<<endl;
            }
            if(x==45) {
                y=55;
                cout<<y<<endl;
            }
            if(x==50) {
                y=55;
                cout<<y<<endl;
            }
            if(x==55) {
                y=60;
                cout<<y<<endl;
            }
            if(x==60) {
                y=70;
                cout<<y<<endl;
            }
            if(x==65) {
                y=70;
                cout<<y<<endl;
            }
            if(x==70) {
                y=75;
                cout<<y<<endl;
            }
            if(x==75) {
                y=85;
                cout<<y<<endl;
            }
            if(x==80) {
                y=85;
                cout<<y<<endl;
            }
            if(x==85) {
                y=90;
                cout<<y<<endl;
            }
            if(x==90) {
                y=100;
                cout<<y<<endl;
                cout<<"Sorry! You lose"<<endl;
                break;
            }
            if(x==95) {
                y=100;
                cout<<y<<endl;
                cout<<"Sorry! You lose"<<endl;
            }
            if(x==100) {
                cout<<"Congratulations! You win"<<endl;
                break;
            }
           }
        }
        else {
            int x,y=10;
            cout<<y<<endl;
            while(1) {
            cin>>x;
            if(x==15) {
                y=20;
                cout<<y<<endl;
            }
            if(x==20) {
                y=30;
                cout<<y<<endl;
            }
            if(x==25) {
                y=30;
                cout<<y<<endl;
            }
            if(x==30) {
                y=40;
                cout<<y<<endl;
            }
            if(x==35) {
                y=40;
                cout<<y<<endl;
            }
            if(x==40) {
                y=45;
                cout<<y<<endl;
            }
            if(x==45) {
                y=55;
                cout<<y<<endl;
            }
            if(x==50) {
                y=55;
                cout<<y<<endl;
            }
            if(x==55) {
                y=60;
                cout<<y<<endl;
            }
            if(x==60) {
                y=70;
                cout<<y<<endl;
            }
            if(x==65) {
                y=70;
                cout<<y<<endl;
            }
            if(x==70) {
                y=75;
                cout<<y<<endl;
            }
            if(x==75) {
                y=85;
                cout<<y<<endl;
            }
            if(x==80) {
                y=85;
                cout<<y<<endl;
            }
            if(x==85) {
                y=90;
                cout<<y<<endl;
            }
            if(x==90) {
                y=100;
                cout<<y<<endl;
                cout<<"Sorry! You lose"<<endl;
                break;
            }
            if(x==95) {
                y=100;
                cout<<y<<endl;
                cout<<"Sorry! You lose"<<endl;
            }
            if(x==100) {
                cout<<"Congratulations! You win"<<endl;
                break;
            }
          }
        }
    }
    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,y;
        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==100) {
                    printf("%s wins",player1);
                    break;
                }
            }
            else if(i%2==0 && first_move==1) {
                printf("turn of %s : ",player2);
                cin>>y;
                if(y==100) {
                    printf("%s wins",player2);
                    break;
                }
            }
            if(i%2!=0 && first_move==2) {
                printf("turn of %s : ",player2);
                cin>>x;
                if(x==100) {
                    printf("%s wins",player2);
                    break;
                }
            }
            else if(i%2==0 && first_move==2){
                printf("turn of %s : ",player1);
                cin>>y;
                if(y==100) {
                    printf("%s wins",player1);
                    break;
                }
            }
        }
    }
    return 0;
}