Answer quastion 4

#include<iostream>
using namespace std;
int main()
{
    int a[4][4],i,j,b[4];
    for(i=0;i<4;i++)
    {
        for(j=0;j<4;j++)
        {
            cout<<"["<<i<<"]["<<j<<"]";
            cin>>a[i][j];
        }
    }
    cout<<"\nBefore rotate secondary diameter\n";
    for(i=0;i<4;i++)
    {
        for(j=0;j<4;j++)
        {
            cout<<a[i][j]<<"\t";
        }
        cout<<endl<<endl;
    }
    cout<<endl;
    for(i=0;i<4;i++)
    {
        b[i]=a[i][3-i];
    }
    for(j=1;j<=5;j++)
    {
        b[4]=b[0];
        for(i=0;i<4;i++)
        {
            b[i]=b[i+1];
        }
    }
    for(i=0;i<4;i++)
    {
        cout<<b[i]<<"\t";
    }
    for(i=0;i<4;i++)
    {
        a[i][3-i]=b[i];
    }
    cout<<"\nAfter rotate secondary diameter\n";
    for(i=0;i<4;i++)
    {
        for(j=0;j<4;j++)
        {
            cout<<a[i][j]<<"\t";
        }
        cout<<endl<<endl;
    }

}