# Sum of all the numbers present at given level in Modified Pascal’s triangle

Given a level N, the task is to find the sum of all the integers present at this given level in an Alternating Pascal’s triangle.
An Modified Pascal triangle with 5 levels is as shown below.

```     1
-1 1
1 -2 1
-1 3 -3 1
1 -4 6 -4 1
```

Examples:

```Input: N = 1
Output: 1

Input: N = 2
Output: 0
```

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

Approach: As we can observe that for even level sum is 0 and for odd level except for 1 sum is also 0. So There can be at most 2 cases:

• If L = 1, then answer is 1.
• Otherwise the answer will always be 0.

Below is the implementation of the above approach:

## C++

 `// C++ program to calculate sum of ` `// all the numbers present at given ` `// level in an Modified Pascal’s triangle ` ` `  `#include ` `using` `namespace` `std; ` ` `  `// Function to calculate sum ` `void` `ans(``int` `n) ` `{ ` `    ``if` `(n == 1) ` `        ``cout << ``"1"``; ` `    ``else` `        ``cout << ``"0"``; ` `} ` ` `  `// Driver Code ` `int` `main() ` `{ ` `    ``int` `n = 2; ` `    ``ans(n); ` ` `  `    ``return` `0; ` `} `

## Java

 `// Java program to calculate sum of ` `// all the numbers present at given ` `// level in an Modified Pascal's triangle ` `class` `GFG  ` `{ ` ` `  `// Function to calculate sum ` `static` `void` `ans(``int` `n) ` `{ ` `    ``if` `(n == ``1``) ` `        ``System.out.println(``"1"``); ` `    ``else` `        ``System.out.println(``"0"``); ` `} ` ` `  `// Driver Code ` `public` `static` `void` `main(String[] args) ` `{ ` `    ``int` `n = ``2``; ` `    ``ans(n); ` `} ` `} ` ` `  `// This code is contributed by 29AjayKumar `

## Python3

 `# Python3 program to calculate sum of  ` `# all the numbers present at given  ` `# level in an Modified Pascal’s triangle  ` ` `  `# Function to calculate sum  ` `def` `ans(n) :  ` ` `  `    ``if` `(n ``=``=` `1``) : ` `        ``print``(``"1"``,end``=``"");  ` `    ``else` `: ` `        ``print``(``"0"``,end``=``"");  ` ` `  `# Driver Code  ` `if` `__name__ ``=``=` `"__main__"` `:  ` ` `  `    ``n ``=` `2``;  ` `    ``ans(n);  ` `     `  `# This code is contributed by AnkitRai01 `

## C#

 `// C# program to calculate sum of ` `// all the numbers present at given ` `// level in an Modified Pascal's triangle ` `using` `System; ` `     `  `class` `GFG  ` `{ ` ` `  `// Function to calculate sum ` `static` `void` `ans(``int` `n) ` `{ ` `    ``if` `(n == 1) ` `        ``Console.WriteLine(``"1"``); ` `    ``else` `        ``Console.WriteLine(``"0"``); ` `} ` ` `  `// Driver Code ` `public` `static` `void` `Main(String[] args) ` `{ ` `    ``int` `n = 2; ` `    ``ans(n); ` `} ` `} ` ` `  `// This code is contributed by 29AjayKumar `

Output:

```0
```

Time Complexity: O(1)

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Improved By : 29AjayKumar, AnkitRai01

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