C Program to Print Hollow Diamond Pattern inside a Square

Write a C Program to print a hollow diamond inside a square star pattern using for loop, while loop, and functions with custom symbols.

C Program to Print Hollow Diamond Pattern inside a Square

In this example, we used multiple nested for loops to iterate the rows and print the hollow diamond pattern inside a square pattern.

#include<stdio.h>
int main(void)
{
    int i, j, k, rows;
    printf("Enter Hollow Diamond inside Square Rows =  ");
    scanf("%d", &rows);
    
    for (i = 1 ; i <= rows; i++ )
    {
        for (j = i ; j <= rows; j++ )
        {
            printf("*");
        }
        for (j = 1 ; j <= 2 * i - 2; j++ )
        {
            printf(" ");
        }
        for (k = i ; k <= rows; k++ )
        {
            printf("*");
        }
        printf("\n");
    }
    
    for (i = 1 ; i <= rows; i++ )
    {
        for (j = 1 ; j <= i; j++ )
        {
            printf("*");
            
        }
        for (k = 2 * i - 2 ; k < 2 * rows - 2; k++ )
        {
            printf(" ");
        }
        for (k = 1 ; k <= i; k++ )
        {
            printf("*");
        }
        printf("\n");
    }
}

In this C hollow diamond star pattern inside a square program, we replace the above for loop code with the while loop and experiment with the if else block to get the result.

#include<stdio.h>
int main(void)  
{
    int i, j, k, rows;
    
    printf("Enter Hollow Diamond inside Square Rows =  ");
    scanf("%d", &rows);
    
    i = 0 ;
    while( i < rows)
    {
        j = 0 ;
        while ( j < rows  )
        {
            if(j < rows - i) {
                printf("*");
            }
            else {
                printf(" ");
            }
            j++;
        }
        k = 0 ;
        while ( k < rows)
        {
            if (k < i ) {
                printf(" ");
            }
            else {
                printf("*");
            }
            k++ ;
        }
        printf("\n");
        i++;
    }
    
    i = 1 ;
    while ( i <= rows )
    {
        j = 0 ;
        while ( j < rows )
        {
            if(j < i) {
                printf("*");
            }
            else {
                printf(" ");
            }
            j++;
        }
        k = 0 ;
        while ( k < rows)
        {
            if (k < rows - i ) {
                printf(" ");
            }
            else {
                printf("*");
            }
            k++ ;
        }
        printf("\n");
        i++;
    }
}

Enter Hollow Diamond inside Square Rows =  9
******************
********  ********
*******    *******
******      ******
*****        *****
****          ****
***            ***
**              **
*                *
*                *
**              **
***            ***
****          ****
*****        *****
******      ******
*******    *******
********  ********
******************

This C hollow diamond Pattern inside a square program is the same as the second example. However, we replaced the static * symbol with the user-entered special character and replaced the while loop with for loop.

#include<stdio.h>
int main(void) 
{
    int i, j, k, rows;
    char ch;
    
    printf("Enter Symbol =  ");
    scanf("%c", &ch);
    
    printf("Enter Hollow Diamond inside Square Rows =  ");
    scanf("%d", &rows);
    
    for (i = 0 ; i < rows; i++ )
    {
        for (j = 0 ; j < rows; j++ )
        {
            if(j < rows - i) {
                printf("%c", ch);
            }
            else {
                printf(" ");
            }
        }
        for (k = 0 ; k < rows; k++ )
        {
            if (k < i ) {
                printf(" ");
            }
            else {
                printf("%c", ch);
            }
        }
        printf("\n");
    }
    
    for (i = 1 ; i <= rows; i++ )
    {
        for (j = 0 ; j < rows; j++ )
        {
            if(j < i) {
                printf("%c", ch);
            }
            else {
                printf(" ");
            }
        }
        for (k = 0 ; k < rows; k++ )
        {
            if (k < rows - i ) {
                printf(" ");
            }
            else {
                printf("%c", ch);
            }
        }
        printf("\n");
    }
}

Enter Symbol =  @
Enter Hollow Diamond inside Square Rows =  9
@@@@@@@@@@@@@@@@@@
@@@@@@@@  @@@@@@@@
@@@@@@@    @@@@@@@
@@@@@@      @@@@@@
@@@@@        @@@@@
@@@@          @@@@
@@@            @@@
@@              @@
@                @
@                @
@@              @@
@@@            @@@
@@@@          @@@@
@@@@@        @@@@@
@@@@@@      @@@@@@
@@@@@@@    @@@@@@@
@@@@@@@@  @@@@@@@@
@@@@@@@@@@@@@@@@@@