Pattern consisting of numbers moving in clockwise direction around a rectangular shape (length and breadth decreasing each time) [closed]

Answer 1

Here is my solution in Java: (I already know that a Pointer points to an specific adress on memory or is declared to make that purpose on C, and because Java does not supports pointers I did this with a non C Pointer logic) So , that said, I did this with the logic of point to the "address" (rown, column) of the matrix.

static void MatrixTravelPointer(int [][] m){
    int pointerX = 0;
    int pointerY = 0;
    List<Integer> elements = new ArrayList<>();

    int maxlength_ = 0;
    int pos = 0;
    for(int i=0;i<m.length;i++){
        maxlength_ +=m[i].length;
    }
    boolean turn = false;
    int turns = 1;

    while(pos<maxlength_)
    {
        System.out.print(" "+m[pointerX][pointerY]);
        elements.add(m[pointerX][pointerY]);

        if( (pointerY == m[0].length - turns && pointerX == m.length - turns)){
            turn = true;
            turns++;
        }

        if(turns > 1 && turn == true && pointerX == turns - 1){
            turn = false;
        }

        if(turn == false){
            if(pointerY < m[0].length - turns){
                pointerY++;
            } else if(pointerX < m.length - turns){
                pointerX++;
            }
        }

        if(turn == true)
        {
            if(pointerY >= turns - 1){
                pointerY--;
            } else if(pointerX >= turns - 1){
                pointerX--;
            }
        }

        pos++;
    }

    System.out.print("\n");
    Iterator it = elements.iterator();
    while(it.hasNext()){
        System.out.print(" "+(int)it.next());
    }
} 

For now my logic only works for cubic and rectangular matrix.
The logic goes like this using a 4x4 matrix:
Pointer travels in the matrix from [0][0] to [0][3] , at this point it turns the travel pointer to go from [0][3] to [3][3], imagine a top down "L" on Tetris ,at this point we can omit or erase the top row and right column and reverse the travel point from right to left using -- and from down to top. Because each time we form an "L" on the "second turn" we need to reduce the travel size (the "L" size) with the "turns" var depending on the times we form an "L".

Answer 2

#include <stdio.h>
#include <stdlib.h>

#define SIZE 5

#define RIGHT 1
#define DOWN 2
#define LEFT 3
#define UP 4


void printArray1(int b[SIZE][SIZE], int size);
void printArray2(int b[SIZE][SIZE], int size);
int move(int b[SIZE][SIZE], int *xpos, int *ypos, int *movem, int number);


int main(void) {


    int i, j, num;
    int dir;
    int a[SIZE][SIZE] = { 0 }; 

    printArray1(a, SIZE);
    printf("\n\n");
    printArray2(a, SIZE);

    dir = RIGHT;
    i = 0;
    j = 0;
    num = 1;
    for (; num <= (SIZE * SIZE); num++ )
        move(a, &i, &j, &dir, num);

    printArray1(a, SIZE);

    printf("\n\n");

    printArray2(a, SIZE);

    return 0;
}




void printArray1 (int b[SIZE][SIZE], int size)
{
    int i, j;
    for ( i = 0; i < size; i++ ) {
        for ( j = 0; j < size; j++ )
            printf("%3d  ", b[j][i]);
        printf("\n");
    }
    printf("\n\n");
    return;
}

void printArray2 (int b[SIZE][SIZE], int size)
{
    int i, j;
    for ( i = 0; i < size; i++ ) {
        for ( j = 0; j < size; j++ )
            printf("%3d  ", b[i][j]);
        printf("\n");
    }
    printf("\n\n");
    return;
}



int move(int b[SIZE][SIZE], int *xpos, int *ypos, int *movem, int number)
{

    int x, y, dirn, reqdDirn;

    x = *xpos;
    y = *ypos;
    dirn = *movem;

    if (b[x][y] == 0 ) {
        b[x][y] = number;
    }


    reqdDirn = dirn;

    switch (dirn) {
    default:
        printf("Unexpected value");
        return;

    case RIGHT:
        x = x + 1;
        if (b[x][y] == 0) {
            if (x > SIZE-1) {
                reqdDirn = DOWN;
                x = SIZE - 1;
                y = y + 1;
                if (y > SIZE-1)
                    y = SIZE - 1;
            }
        } else {
            // just step back and change direction
            x = x - 1;
            y = y + 1;
            reqdDirn = DOWN;
        }
        break;
    case DOWN:
        y = y + 1;
        if (b[x][y] == 0) {
            if (y > SIZE-1) {
                reqdDirn = LEFT;
                y = SIZE - 1;
                x = x - 1;
                if (x < 0)
                    x = 0;
            }
        } else {
            y = y - 1;
            x = x - 1;
            reqdDirn = LEFT;
        }
        break;
    case LEFT:
        x = x - 1;
        if (b[x][y] == 0) {
            if (x < 0) {
                reqdDirn = UP;
                x = 0;
                y = y - 1;
                if (y < 0)
                    y = 0;
            }
        } else {
            // just step back and change direction
            x = x + 1;
            y = y - 1;
            reqdDirn = UP;
        }
        break;
    case UP:
        y = y - 1;
        if (b[x][y] == 0) {
            if (y < 0) {
                reqdDirn = RIGHT;
                y = 0;
                x = x + 1;
                if (x > SIZE-1)
                    x = SIZE - 1;
            }
        } else {
            // just step back and change direction
            y = y + 1;
            x = x + 1;
            reqdDirn = RIGHT;
        }
        break;

    }


    *xpos = x;
    *ypos = y;
    *movem = reqdDirn;

}


 Output

  1    2    3    4    5  
 16   17   18   19    6  
 15   24   25   20    7  
 14   23   22   21    8  
 13   12   11   10    9  




  1   16   15   14   13  
  2   17   24   23   12  
  3   18   25   22   11  
  4   19   20   21   10  
  5    6    7    8    9  

Answer 3

//In java
package ds1;

public class SpiralMatrix {

    public static void main(String[] args) throws Exception{
          int[][] values = {{1,2,3,4,5}, {6,7,8,9,10}, {11,12,13,14,15},{16,17,18,19,20},{21,22,23,24,25}};
            int x=0,y=0,z=0 ,length=values.length;
            System.out.println("Jai ShRaam \n array size :"+length+" \n \n");
        //Logic Starts
        for (int i=0;i<values.length;i++ )
        {
            for (int j=0;j<values.length;j++ )
            {

                if(i==j){
                            for(int k=i;k<length-i;k++)
                            {
                                System.out.print(values[x][k]+" , ");
                            }
                            x++;y++;

                            for(int k=x;k<length-i;k++)
                            {
                                System.out.print(values[k][length-x]+" ; ");
                            }
                            y++;
                            for(int k=i+length-y;k>=i;k--)
                            {
                                System.out.print(values[length-x][k]+" - ");
                            }
                            for(int k=i+length-y;k>=x;k--)
                            {
                                System.out.print(values[k][i]+" : ");
                            }

                }//end of i==j
            }//end of j loop
            //System.out.println();
        }
        //Logic ends

    }//end of psvm

}

//Answer 1 , 2 , 3 , 4 , 5 , 10 ; 15 ; 20 ; 25 ; 24 - 23 - 22 - 21 - 16 : 11 : 6 : 7 , 8 , 9 , 14 ; 19 ; 18 - 17 - 12 : 13 ,