C++ Program To Print Right Half Pyramid Pattern

Here we will build a C++ Program To Print Right Half Pyramid Pattern with the following 2 approaches:

1. Using for loop 
2. Using while loop

Input:

rows = 5 

Output: 

* 
* * 
* * * 
* * * * 
* * * * *  

1. Using for loop

First for loop is used to identify the number of rows and the second for loop is used to identify the number of columns. Here the values will be changed according to the first for loop. 

C++

// C++ Program To Print Right Half
// Pyramid Pattern using for loop
#include <iostream>
using namespace std;

int main()
{
    int rows = 5;

    // first for loop is used to identify number of rows
    for (int i = 1; i <= rows; i++) {

        // second for loop is used to identify number of
        // columns and here the values will be changed
        // according to the first for loop
        for (int j = 1; j <= i; j++) {

            // printing the required pattern
            cout << "* ";
        }
        cout << "\n";
    }
    return 0;
}

Output

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

Time complexity: O(n²) 

Here n is number of rows.

Space complexity: O(1)

As constant extra space is used.

2. Using while loop

The while loops check the condition until the condition is false. If condition is true then enters in to loop and execute the statements. 

C++

// C++ Program To Print Right Half
// Pyramid Pattern using while loop
#include <iostream>
using namespace std;

int main()
{

    int i = 0, j = 0;

    int rows = 5;

    // while loop check the condition until the given
    // condition is false if it is true then enteres in to
    // the loop
    while (i < rows) {

        // this loop will print the pattern
        while (j <= i) {
            cout << "* ";
            j++;
        }
        j = 0;
        i++;
        cout << "\n";
    }
    return 0;
}

Output

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

Time complexity: O(n²) where n is number of rows

Space complexity: O(1)