Question 1
#include <iostream>
using namespace std;

int main()
{
	int number[4][4] = {{0, 1, 2, 3}, {4, 5, 6, 7}, {8, 9, 10, 11}, {12, 13, 14, 15}};
	int row, col;

	while (1)
	{
		do {
			cout << "Row number = ";
			cin >> row;
		} while ((row < 0) || (row >=4));

		do {
			cout << "Column number = ";
			cin >> col;
		} while ((col < 0) || (col >=4));

		cout << "Content = " << number[row][col] << endl;
	}

	return 0;
}

Question 2
#include <iostream>
using namespace std;

int main()
{
        int t1[4][4], t2[4][4], t3[4][4];
        int i, j;

        for(i=0;i<4;i++){
                cout << "Enter the row "<<i<<" elements of table 1: ";
                for(j=0;j<4;j++)
                    cin >> t1[i][j];
        }
        for(i=0;i<4;i++){
                cout << "Enter the row "<<i<<" elements of table 2: ";
                for(j=0;j<4;j++)
                    cin >> t2[i][j];
        }

        for(i=0;i<4;i++){
                for(j=0;j<4;j++)                
                        t3[i][j]=t1[i][j]+t2[i][j];
        }

        cout << "The sum of these two tables is";
        for(i=0;i<4;i++){
                for(j=0;j<4;j++)
                    cout << t3[i][j];
                cout << endl;
        }

	return 0;
}

Question 3
#include <iostream>
using namespace std;

int main()
{
	char c[4][4] = {{'a', 'b', 'c', 'd'}, {'e', 'f', 'g', 'h'}, {'i', 'j', 'k', 'l'}, {'m', 'n', 'o', 'p'}};
	int i, j, choice, x, y, temp;

	while (1)
	{
		for (i=0; i<4; i++)
		{
			for (j=0; j<4; j++)
				cout << c[i][j];
			cout << endl;
		}
		cout << endl;

		do {
			cout << "Row (1) or Col (2)? ";
			cin >> choice;
		} while ((choice != 1) && (choice != 2));

		do {
			if (choice == 1)
				cout << "Enter the row numbers: ";
			else
				cout << "Enter the column numbers: ";
			cin >> x >> y;
		} while ((x < 0) || (x > 3) || (y < 0) || (y > 3));

		cout << endl;

		if (choice == 1)
			for (j=0; j<4; j++)		// swap row x and y
			{
				temp = c[x][j];
				c[x][j] = c[y][j];
				c[y][j] = temp;
			}
		else
			for (i=0; i<4; i++)		// swap column x and y
			{
				temp = c[i][x];
				c[i][x] = c[i][y];
				c[i][y] = temp;
			}
	}
	return 0;
}

Question 4
#include <iostream>
using namespace std;
int main()
{
    int n, i, j, numbers[10][10];
    
    do{
        cout << "Input n: ";
        cin >> n;
    }while(n<1||n>10);
    
    for(i=0;i<n;i++){
        for(j=0;j<n;j++)
            numbers[i][j]=i*5+j;
    }
    for(i=0;i<n;i++){
        for(j=0;j<n;j++)
            cout << numbers[i][j] << "\t";
        cout << endl;
    }
    return 0;
}

Question 5
#include <iostream>
using namespace std;
int main()
{
    int n, i, j;
    char numbers[5][5];
    
    do{
        cout << "Input n: ";
        cin >> n;
    }while(n<1||n>5);
    
    for(i=0;i<n;i++){
        for(j=0;j<n;j++)
            numbers[j][i]=(char)('a'+i*5+j);
    }
    for(i=0;i<n;i++){
        for(j=0;j<n;j++)
            cout << numbers[i][j] << "\t";
        cout << endl;
    }
    return 0;
}




Challenging question
Question 4

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


int main()
{

    int s=6,i,j,r,c;
    char board[s][s];
    int uncover = (s-2)*(s-2)-s;
    bool endgame = false;

    // initialise board
    for(i=0;i<s;i++){
        for(j=0;j<s;j++)
            board[i][j]='-';
    }
    // place bomb
    srand(time(NULL));

    for(i=0;i<s;i++){
        do{
            r=rand()%(s-2)+1;
            c=rand()%(s-2)+1;
        }while(board[r][c]=='b');
        board[r][c]='b';
    }
    do{
        // print board
        cout << "  1 2 3 4" << endl;
        for(i=1;i<s-1;i++){
            cout << i << " ";
            for(j=1;j<s-1;j++){
                if(board[i][j]=='b')
                    cout << "- ";
                else
                    cout << board[i][j] << " " ;
            }
            cout << endl;
        }
        // user input
        do{
            cout << "Enter row number and col number: ";
            cin >> r >> c;
        }while(r<1||r>4||c<1||c>4);

        // check & update board

        if(board[r][c]=='b')
            endgame = true;
        else{
            uncover--;
                int count=0;
                for(i=r-1;i<=r+1;i++)
                        for(j=c-1;j<=c+1;j++){
                                if(board[i][j]=='b')
                                        count++;
                        }
            board[r][c]='0'+ count;
        }


    }while(!endgame&&uncover>0);

    if(uncover == 0)
        cout << endl << "You win! "<< endl;
    else{
        cout << endl << "You lose! "<< endl;
                cout << "  1 2 3 4" << endl;
        for(i=1;i<s-1;i++){
            cout << i << " ";
            for(j=1;j<s-1;j++){
                cout << board[i][j] << " " ;
            }
            cout << endl;
        }
    }
    return 0;
}