hdoj：2034

#include <iostream>
#include <vector>
#include<algorithm> //包含sort函数
using namespace std;

int main()
{
    int n, m;
    int a[], b[];
    bool c[];
    while (cin >> n >> m && (m || n))
    {
        int count = ;
        for (int i = ; i <= n; i++)
        {
            cin >> a[i];

        }
        for (int i = ; i <= n; i++)
        {
            c[i] = true;
        }
        for (int j = ; j <= m; j++)
            cin >> b[j];

        for (int i = ; i <= n; i++)
        {
            for (int j = ; j <= m; j++)
            {
                if (a[i] == b[j])
                {
                    c[i] = false;
                    count++;
                }
            }
        }

        if (n ==  && m == )
            break;
        if (n == )
        {
            cout << "NULL" << endl;
            continue;
        }

        if (m ==  || count==)
        {
            for (int i = ; i < n; i++)
                cout << a[i]<<" ";
            cout << a[n] << " " << endl;
            continue;
        }

        for (int i = ; i <= n; i++)
        {
            if (c[i]==true)
            {
                cout << a[i] << " ";
            }

        }
        cout << endl;

    }
}

不明白为什么错误