问我怎样才能使我的struct的变量在所有函数中都可见？

EN

#include <stdlib.h>
#include <stdio.h>
#include <iostream>
using namespace std;

struct va{

public:
    int i, j, k, l; //for possible loops or variables I only need for a very short time
    int id = 0;
    int name = id+1;
    // like 6 other ints I also declared here, including year2
    int achi = year2+1;
    //The above is for easier identification of pro[whatever][needed data]. The +1 method is to allow for easier editing later.

    int size = 20, row = 0; //This is important for addition
    string searchterm = ""; //this is for searching

public:
    int main();
    void MainMenu();
    void Addition();
    void Deletion();
    void Search();
    void Modify();
    void List();
};

void MainMenu();
void Addition();
void Deletion();
void Search();
void Modify();
void List(); 
//I just find it neater to make side functions after the main one.

int main()
{
    setlocale(LC_ALL, "");


    const int column = achi;
    const int initsize = size; //These two are so I can edit the size of the array from the struct directly
    string pro[initsize][column]; //This creates the array that's the actual database

    cout << endl << "Welcome to the League of Legends Pro Players database!" << endl << endl;
    cout << endl << "Please, use the menu to access its functions.";

    MainMenu();

    cout << endl;
    return 0; 
}

void MainMenu()
{
    cout << endl << "Main Menu" << endl;
    cout << endl << "1: add an entry to the database.";
    cout << endl << "2: delete an existing entry from the database.";
    cout << endl << "3: search for an existing entry in the database.";
    cout << endl << "4: modify an existing entry.";
    cout << endl << "5: list all existing entries." << endl;

    cin  >> i;

    switch(i)
    {
        case 1: Addition();
        case 2: Deletion();
        case 3: Search();
        case 4: Modify();
        case 5: List();
    }
}