Incrementing + Inverted Squared Number-Star (Alternate Type 3)

Understanding the Problem

The goal is to print an alternate inverted squared number-star pattern where row order alternates in a different way.

Pattern Explanation

The pattern follows a grid structure where numbers increase sequentially, but certain rows are positioned differently.

1*2*3*4
9*10*11*12
17*18*19*20
13*14*15*16
5*6*7*8
            

Observations:

  • The pattern consists of 5 rows and 4 columns.
  • Numbers increment from left to right across the grid.
  • Each number is followed by a '*', except the last number in each row.
  • Rows are arranged in a specific order, where the third row has the highest numbers.

Algorithm

The pattern follows these steps:

  1. Initialize a number counter starting from 1.
  2. Store values in a 2D array as they increment.
  3. Rearrange row positions based on the required output order.
  4. Within each row, print numbers left to right with '*'.
  5. Move to the next line after printing each row.

Method 1: Using Nested Loops

This method first stores values in an array and then prints them in the required alternating order.

#include <stdio.h>

void printPattern(int n) {
    int arr[n][n], num = 1;
    
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            arr[i][j] = num++;
        }
    }
    
    int order[] = {0, 2, 4, 3, 1}; // Custom row order for printing
    
    for (int i = 0; i < n; i++) {
        int row = order[i];
        for (int j = 0; j < n; j++) {
            printf("%d", arr[row][j]);
            if (j < n - 1) printf("*");
        }
        printf("\n");
    }
}

int main() {
    int size = 5;
    printPattern(size);
    return 0;
}
            

Output:

1*2*3*4
9*10*11*12
17*18*19*20
13*14*15*16
5*6*7*8