Given a complete binary tree of depth **H**. If the mirror image from the left and the right side of this tree is taken then:

Right Mirrored Image:Rightmost node of the every level is connected to mirrored corresponding node.

Left Mirrored Image:Left most node of the every level is connected to mirrored corresponding node.

The task is to find the number of edges after taking both the mirror images in the final tree.

**Examples:**

Input:H = 1

Output:10

2 edges in the original tree will get mirrored in the mirror images (left and right) i.e. 6 edges in total.

And the edges connecting the mirror images with the original tree as shown in the image above.

Input:H = 2

Output:24

(6 * 3) + 3 + 3 = 24

**Approach:** Maintain the leftmost, rightmost nodes after each mirror image. Number of edges will change after each operation of mirror image. Initially,

**After right mirrored image: **

**After left mirrored image: **

**In complete modified tree: **

Below is the implementation of the above approach:

## C++

`// C++ implementation of the approach ` `#include <bits/stdc++.h> ` `using` `namespace` `std; ` ` ` `// Function to return the total number ` `// of edges in the modified tree ` `int` `countEdges(` `int` `H) ` `{ ` ` ` ` ` `int` `edges, right, left; ` ` ` `edges = 2 * (` `pow` `(2, H) - 1); ` ` ` `left = right = H + 1; ` ` ` ` ` `// Total edges in the modified tree ` ` ` `int` `cnt = (edges * 3) + left + right; ` ` ` `return` `cnt; ` `} ` ` ` `// Driver code ` `int` `main() ` `{ ` ` ` `int` `H = 1; ` ` ` ` ` `cout << countEdges(H); ` ` ` ` ` `return` `0; ` `} ` |

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## Java

`// Java implementation of the approach ` `import` `java.io.*; ` ` ` `class` `GFG { ` ` ` ` ` `// Function to return the total number ` ` ` `// of edges in the modified tree ` ` ` `static` `int` `countEdges(` `int` `H) ` ` ` `{ ` ` ` ` ` `int` `edges, right, left; ` ` ` `edges = ` `2` `* (` `int` `)(Math.pow(` `2` `, H) - ` `1` `); ` ` ` `left = right = H + ` `1` `; ` ` ` ` ` `// Total edges in the modified tree ` ` ` `int` `cnt = (edges * ` `3` `) + left + right; ` ` ` `return` `cnt; ` ` ` `} ` ` ` ` ` `// Driver code ` ` ` `public` `static` `void` `main(String[] args) ` ` ` `{ ` ` ` `int` `H = ` `1` `; ` ` ` `System.out.println(countEdges(H)); ` ` ` `} ` `} ` ` ` `// This code has been contributed by anuj_67.. ` |

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## Python 3

`# Python 3 implementation of the approach ` ` ` `# Function to return the total number ` `# of edges in the modified tree ` `def` `countEdges( H): ` ` ` ` ` `edges ` `=` `2` `*` `(` `pow` `(` `2` `, H) ` `-` `1` `) ` ` ` `left ` `=` `right ` `=` `H ` `+` `1` ` ` ` ` `# Total edges in the modified tree ` ` ` `cnt ` `=` `(edges ` `*` `3` `) ` `+` `left ` `+` `right ` ` ` `return` `cnt ` ` ` `# Driver code ` `if` `__name__ ` `=` `=` `"__main__"` `: ` ` ` `H ` `=` `1` `; ` ` ` ` ` `print` `(countEdges(H)) ` ` ` `# This code is contributed by ChitraNayal ` |

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## C#

`// C# implementation of the approach ` `using` `System; ` ` ` `class` `GFG ` `{ ` ` ` ` ` `// Function to return the total number ` ` ` `// of edges in the modified tree ` ` ` `static` `int` `countEdges(` `int` `H) ` ` ` `{ ` ` ` ` ` `int` `edges, right, left; ` ` ` ` ` `edges = 2 * (` `int` `)(Math.Pow(2, H) - 1); ` ` ` `left = right = H + 1; ` ` ` ` ` `// Total edges in the modified tree ` ` ` `int` `cnt = (edges * 3) + left + right; ` ` ` `return` `cnt; ` ` ` `} ` ` ` ` ` `// Driver code ` ` ` `public` `static` `void` `Main() ` ` ` `{ ` ` ` `int` `H = 1; ` ` ` `Console.WriteLine(countEdges(H)); ` ` ` `} ` ` ` `} ` ` ` `// This code is contributed by AnkitRai01 ` |

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**Output:**

10

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