连接四个C 下降功能无法正常工作

我在连接4的代码方面遇到了麻烦。是我的下降功能是错误的还是我的主要功能？

#include <iostream>
using namespace std;
void drop(int b[][7], int column, int disc)//drops the game pieces  {
    for (int i = 5; i >= 0; i--)//starts at 5(the bottom) {
        if (b[i][column - 1] == 0)//if row 5 is not filled it will be 1
        {
            b[i][column - 1] = disc;
            break;
        }
        if (b[i][column - 1] != 0)//if row 5 is filled go to next row
        {
            b[i - 1][column - 1] = disc;
            break;
        }
    }
}
void display(int c[][7])//displays the gameboard
{
    for (int i = 0; i < 6; i++)
    {
        for (int j = 0; j < 7; j++)
        {
            cout << c[i][j];
        }
        cout << endl;
    }
    cout << endl;
}
void initial(int arr[][7])//sets the initial gameboard with all 0's
{
     for (int i = 0; i < 6; i++)
     {
         for (int j = 0; j < 7; j++)
         {
             arr[i][j] = 0;
         }
     }
}
void main()
{
    int a[6][7];//declare the 2d array 
    int column;//declares the variable for column
    initial(a);
    display(a);//prints the initial 
    cout << "Enter 0 if you win or want to quit"<<endl;//user exit
    for (;;)//infinite for loop so the game will continue until user exits
    {
        cout << "Enter column 1-7 ";
        cin >> column;//reading in what the user has inputted
        if (column == 0)//if it is 0 the program will end
            break;
        drop(a, column, 1);//player 1
        display(a);//displays board after player 1 put piece in
        cout << "Enter column 1-7 ";
        cin >> column;
        if (column == 0)
            break;
        drop(a, column, 2);//player 2
        display(a);//displays board after player 2 put piece in
    }
}