CODEWITHSUNDEEP
cfor-loopnumeric
No_name_instant
No_name_instant

Reputation: 11

How to print numerical pattern with for loop in c

I have tried like this, but I can print this pattern correctly only for 4.

When I give 5,2 or other numbers as input the code fails...

How can I modify this program to match the exact output? I have searched in many platforms but cannot find the answer..

This is the expected output:

input: 2

2 2 2
2 1 2 
2 2 2

input: 5

5 5 5 5 5 5 5 5 5 
5 4 4 4 4 4 4 4 5 
5 4 3 3 3 3 3 4 5 
5 4 3 2 2 2 3 4 5 
5 4 3 2 1 2 3 4 5 
5 4 3 2 2 2 3 4 5 
5 4 3 3 3 3 3 4 5 
5 4 4 4 4 4 4 4 5 
5 5 5 5 5 5 5 5 5

input: 7

7 7 7 7 7 7 7 7 7 7 7 7 7 
7 6 6 6 6 6 6 6 6 6 6 6 7 
7 6 5 5 5 5 5 5 5 5 5 6 7 
7 6 5 4 4 4 4 4 4 4 5 6 7 
7 6 5 4 3 3 3 3 3 4 5 6 7 
7 6 5 4 3 2 2 2 3 4 5 6 7 
7 6 5 4 3 2 1 2 3 4 5 6 7 
7 6 5 4 3 2 2 2 3 4 5 6 7 
7 6 5 4 3 3 3 3 3 4 5 6 7 
7 6 5 4 4 4 4 4 4 4 5 6 7 
7 6 5 5 5 5 5 5 5 5 5 6 7 
7 6 6 6 6 6 6 6 6 6 6 6 7 
7 7 7 7 7 7 7 7 7 7 7 7 7

Here is the code:

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

int main() {
    int n;
    scanf("%d", &n);
    // Complete the code to print the pattern.
    int limit = (n * 2) - 1;
    int row, column;

    for (row = 1; row <= limit; row++) {
        for (column = 1; column <= limit; column++) {
            if (column == 1 || column == 7 || row == 1 || row == 7)
                printf("%d ", n);
            else if (column == 2 || column == 6 || row == 2 || row == 6)
                printf("%d ", n - 1);
            else if (column == 3 || column == 5 || row == 3 || row == 5)
                printf("%d ", n - 2);
            else if (column == 4 || column == 4 || row == 4 || row == 4)
                printf("%d ", n - 3);
        }
        printf("\n");
    }
    return 0;
}

Upvotes: 1

Views: 69

Answers (1)

William Pursell
William Pursell

Reputation: 212268

You are working too hard. (Or, depending on your point of view, not working hard enough!). Instead of chaining a lot of if statments, just compute the value based on the current location. Something like:

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

#define max(x, y) ((x) > (y) ? (x) : (y))

int
main(int argc, char **argv)
{
    char *k = "";
    int n = argc > 1 ? strtol(argv[1], &k, 10) : 5;
    if( *k || n > 9 || n < 1 ){
        fprintf(stderr, "Invalid argument.  Must be 0 < n < 10\n");
        return 1;
    }
    for( int x = 1 - n; x < n; x += 1 ){
        for( int y = n - 1; y > -n; y -= 1 ){
            printf("%d", 1 + max(abs(x),abs(y)));
            putchar(y == 1 - n ? '\n' : ' ');
        }
    }
}

Upvotes: 2

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