Skip to content
Related Articles

Related Articles

Print pattern using only one loop | Set 1 (Using setw)

View Discussion
Improve Article
Save Article
  • Difficulty Level : Easy
  • Last Updated : 13 Sep, 2022
View Discussion
Improve Article
Save Article

Print simple patterns like below using single line of code under loop. Examples:

Input : 5
Output :
    *
   **
  ***
 ****
*****

Input : 6
Output :
     *
    **
   ***
  ****
 *****
******

setw(n) Creates n columns and fills these n columns from right. We fill i of them with a given character, here we create a string with i asterisks using string constructor. setfill() Used to set fill character in a stream. Here we use it to fill remaining n-i-1 places with space (or ‘ ‘) in n columns. 

CPP




// CPP program to print a pattern using only
// one loop. <iomanip> is header file for stfill()
// and setw()
#include<iostream>
#include<iomanip>
using namespace std;
 
void generatePattern(int n)
{
    // Iterate for n lines
    for (int i=1 ; i<=n ; i++)
        cout << setfill(' ') << setw(n)
            << string(i, '*') << endl;
 
    // Remove multi-line commenting characters below
    // to get PATTERN WITH CHARACTERS IN LEFT AND
    // SPACE IN RIGHT
    /* for (int i=1 ; i<=n ; i++)
        cout << left << setfill(' ')
            << setw(n) << string(i,'*') << endl; */
}
 
// Driver code
int main()
{
    int n = 6;
    generatePattern(n);
    return 0;
}

Output:

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

Time complexity: O(n) for given input n

Auxiliary space: O(1)

Please refer below post for one more approach. Print pattern using only one loop | Set 2 (Using Continue) This article is contributed by Sakshi Tiwari. If you like GeeksforGeeks( We know you do! ) and would like to contribute, you can also write an article using write.geeksforgeeks.org or mail your article to review-team@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.

My Personal Notes arrow_drop_up
Recommended Articles
Page :

Start Your Coding Journey Now!