Program to print the Zigzag pattern

Given a number N denoting the number of rows. The task is to print the zigzag pattern with N rows as shown in the below examples.

Examples:

Input : N = 3 
Output : 1 
         3*2 
         4*5*6

Input : N = 5
Output : 1 
         3*2 
         4*5*6 
         10*9*8*7 
         11*12*13*14*15

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Approach:

Use a for loop for printing the number of rows.
Use two variables var and var1 for odd and even rows respectively.
When the row number is odd, calculate starting point of the row and then print and increment the variable simultaneously.
When the row number is even, calculate corresponding starting point and print and decrement the variable simultaneously.

Below is the implementation of the above approach:

C++

// CPP program to print the given 
// zigzag pattern 
  
#include<iostream> 
using namespace std; 
  
// Function to print the zigzag pattern  
void printPattern(int n) 
{    
    int var1, var = 1; 
      
    for(int i = 1; i <= n; i++) 
    {    
        // for odd rows 
        if(i%2!=0) 
        {    
            // calculate starting value 
            var = var + i - 1; 
            for(int j=1; j<=i; j++) 
            { 
                if(j==1) 
                { 
                    cout<<var; 
                } 
                else
                   cout<<"*"<<var; 
                     
               var++;     
            } 
        } 
        else // for even rows 
        {          
            var1 = var + i -1; // calculate starting value  
            for(int j=1; j<=i; j++) 
            { 
                if(j==1) 
                { 
                    // print without star 
                    cout<<var1; 
                } 
                else
                { 
                    // print with star 
                    cout<<"*"<<var1; 
                } 
                var1--; 
            } 
        }  
        cout<<endl; 
    } 
      
} 
  
// Driver code 
int main() 
{ 
    int n = 5; 
      
    printPattern(n); 
      
    return 0; 
}   

Java

// Java program to print the given  
// zigzag pattern  
class GFG 
{ 
// Function to print the  
// zigzag pattern  
static void printPattern(int n)  
{  
    int var1, var = 1;  
      
    for(int i = 1; i <= n; i++)  
    {  
        // for odd rows  
        if(i % 2 != 0)  
        {  
            // calculate starting value  
            var = var + i - 1;  
            for(int j = 1; j <= i; j++)  
            {  
                if(j == 1)  
                {  
                    System.out.print(var);  
                }  
                else
                System.out.print("*" + var);  
                      
            var++;  
            }  
        }  
        else // for even rows  
        {      
            var1 = var + i -1; // calculate starting value  
            for(int j = 1; j <= i; j++)  
            {  
                if(j == 1)  
                {  
                    // print without star  
                    System.out.print(var1);  
                }  
                else
                {  
                    // print with star  
                    System.out.print("*" + var1);  
                }  
                var1--;  
            }  
        }  
        System.out.print("\n");  
    }  
      
}  
  
// Driver code  
public static void main(String [] arg)  
{  
    int n = 5;  
      
    printPattern(n);  
} 
}  
  
// This code is contributed by Smitha 

Python3

# Python3 program to print the given 
# zigzag pattern 
  
# Function to print the zigzag pattern  
def printPattern(n): 
      
    var = 0
    var = 1
      
    for i in range(1, n + 1): 
  
        # for odd rows 
        if(i % 2 != 0): 
              
            # calculate starting value 
            var = var + i - 1
            for j in range(1, i + 1): 
              
                if(j == 1): 
                  
                    print(var, end = "") 
                else: 
                    print("*", end = "") 
                    print(var, end = "") 
                      
                var += 1
              
          
        else: # for even rows 
                  
            var1 = var + i -1 # calculate starting value  
            for j in range(1, i + 1): 
              
                if(j == 1): 
                  
                    # prwithout star 
                    print(var1, end = "") 
                  
                else: 
                  
                    # prwith star 
                    print("*", end = "") 
                    print(var1, end = "") 
                  
                var1 -= 1
              
        print() 
      
# Driver code 
n = 5
  
printPattern(n) 
  
# This code is contributed by Mohit kumar 

C#

// C# program to print the given  
// zigzag pattern  
using System; 
class GFG 
{ 
// Function to print the  
// zigzag pattern  
static void printPattern(int n)  
{  
    int var1, var = 1;  
      
    for(int i = 1; i <= n; i++)  
    {  
        // for odd rows  
        if(i % 2 != 0)  
        {  
            // calculate starting value  
            var = var + i - 1;  
            for(int j = 1; j <= i; j++)  
            {  
                if(j == 1)  
                {  
                    Console.Write(var);  
                }  
                else
                    Console.Write("*" + var);  
                      
            var++;  
            }  
        }  
        else // for even rows  
        {      
            var1 = var + i -1; // calculate starting value  
            for(int j = 1; j <= i; j++)  
            {  
                if(j == 1)  
                {  
                    // print without star  
                    Console.Write(var1);  
                }  
                else
                {  
                    // print with star  
                    Console.Write("*" + var1);  
                }  
                var1--;  
            }  
        }  
        Console.Write("\n");  
    }  
      
}  
  
// Driver code  
public static void Main()  
{  
    int n = 5;  
      
    printPattern(n);  
} 
}  
  
// This code is contributed 
// by Akanksha Rai(Abby_akku) 

PHP

<?php 
// PHP program to print the given  
// zigzag pattern  
  
// Function to print the zigzag pattern  
function printPattern($n)  
{  
    $var1; $var = 1;  
      
    for($i = 1; $i <= $n; $i++)  
    {  
        // for odd rows  
        if($i % 2 != 0)  
        {  
            // calculate starting value  
            $var = $var + $i - 1;  
            for($j = 1; $j <= $i; $j++)  
            {  
                if($j == 1)  
                {  
                    echo $var;  
                }  
                else
                    echo "*" . $var;  
                      
                $var++;  
            }  
        }  
        else // for even rows  
        {      
            // calculate starting value  
            $var1 = $var + $i - 1;  
            for($j = 1; $j <= $i; $j++)  
            {  
                if($j == 1)  
                {  
                    // print without star  
                    echo $var1;  
                }  
                else
                {  
                    // print with star  
                    echo "*" . $var1;  
                }  
                $var1--;  
            }  
        }  
        echo "\n";  
    }  
      
}  
  
// Driver code  
$n = 5;  
  
printPattern($n);  
  
// This code is contributed by Rajput-Ji 
?> 

Output:

1
3*2
4*5*6
10*9*8*7
11*12*13*14*15

My Personal Notes

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

C++

Java

Python3

C#

PHP

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