C Program to Print Cross Star Pattern

Introduction

A cross star pattern is a symmetrical pattern where stars (*) are arranged in such a way that they form a cross. This exercise helps in understanding how to use nested loops and conditional statements to control the placement of stars and spaces.

Problem Statement

Create a C program that:

• Accepts the size of the pattern (which should be odd).
• Prints a cross-shaped star pattern.

Example:

• Input: size = 5
• Output:

  *   *
   * *
    *
   * *
  *   *
  

Solution Steps

1. Input the Size: The size determines the height and width of the pattern. The size should be odd to create a symmetrical cross.
2. Use Nested Loops: The outer loop controls the rows, and the inner loop controls the columns for printing stars and spaces.
3. Conditionally Print Stars: Stars are printed on the middle row and the middle column of each row, while spaces are printed in the other positions.

C Program

#include <stdio.h>

int main() {
    int i, j, size;

    // Step 1: Accept the size of the pattern
    printf("Enter the size (odd number) for the cross pattern: ");
    scanf("%d", &size);

    // Step 2: Outer loop for rows
    for (i = 1; i <= size; i++) {
        // Step 3: Inner loop for columns
        for (j = 1; j <= size; j++) {
            // Step 4: Print stars for the middle column and diagonal (forming the cross)
            if (i == j || j == (size - i + 1)) {
                printf("*");
            } else {
                printf(" ");
            }
        }
        // Move to the next line after each row
        printf("\n");
    }

    return 0;
}

Explanation

Step 1: Input Size

• The program starts by asking the user to input the size of the pattern. The size should be an odd number to create a symmetrical cross.

Step 2: Outer Loop for Rows

• The outer loop controls how many rows are printed. It runs from 1 to size.

Step 3: Inner Loop for Columns

• The inner loop controls the columns, printing stars or spaces.

Step 4: Conditional Printing

• Stars (*) are printed in the middle column (i == j) and the opposite diagonal (j == size - i + 1).
• Spaces are printed in all other positions to form the cross shape.

Output Example

For size = 5, the output will be:

*   *
 * *
  *
 * *
*   *

For size = 7, the output will be:

*     *
 *   *
  * *
   *
  * *
 *   *
*     *

Conclusion

This C program prints a cross-star pattern using nested loops and conditional logic. The program prints stars on the diagonals to form the cross shape while printing spaces in other positions. This exercise is useful for practicing loop control and conditional statements in C programming.