Program to print the given number pattern
1
12
123
1234
12345

C Programming Language / Loop control in C Language

15847

Program:

/**
 * C program to print number pattern
 * www.atnyla.com
 */

#include <stdio.h>

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

    printf("Enter N: ");
    scanf("%d", &N);

    for(i=1; i<=N; i++)
    {
        // Logic to print numbers
        for(j=1; j<=i; j++)
        {
            printf("%d", j);
        }

        printf("\n");
    }

    return 0;
}

Output:

Enter N: 5
1
12
123
1234
12345

Explanation:

Required knowledge

Basic C programming, Loop

Logic to print the given number pattern 1

Logic to this pattern is pretty simple; to understand the logic, first have a careful eye on to the pattern for a minute and think the logic. You can observe that there are N number of rows (where N is the total number of rows to be printed). Each row exactly contains i number of columns (where i is the current row number). And for each row in each column j gets printed (where j is the current column number).
The step-by-step descriptive logic is:

  1. To iterate through rows, run an outer loop from 1 to N.
  2. To print the number, run an inner loop from 1 to i (where i is the current row number). Inside this loop print the value of j (where j is the current column number).

Lets implement this logic.


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