请大家帮我看看这个小程序错在哪了？谢谢！！！

#include <iostream>
using namespace std;
int main()
{
    int i,j,b [4][4]
        int a[4][4]={{1,2,3,4},{5,6,7,8},{9,10,11,12},{13,14,15,16}};
    cout <<"Before converting" <<endl;
    for (i=0;i<4;i++)
    {
        for (j=0;j<4;j++)
        {
            cout.width(4);
            cout<<a[i][j];
        }
        cout <<endl;
    }
    for (i=0;i<4;i++)
        for (j=0;j<4;j++)
            b[j][i]=a[i][j];
        cout<<"after converting"<<endl;
        for (i=0;i<4;i++)
        {
            for (j=0;j<4;j++)
            {
                cout.width(4);
                cout<<b[i][j];
            }
            cout<<endl;
        }
        return 0;
}