# Program to print the Zigzag pattern

• Difficulty Level : Medium
• Last Updated : 11 Aug, 2021

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```

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Approach

1. Use a for loop for printing the number of rows.
2. Use two variables var and var1 for odd and even rows respectively.
3. When the row number is odd, calculate starting point of the row and then print and increment the variable simultaneously.
4. 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``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<

## 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

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## Javascript

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

Time Complexity: O(N^2)
Auxiliary Space: O(1)

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