Related Articles
Find the conjugate of a Complex number
• Last Updated : 27 Aug, 2020

Given a complex number str in the form of a string, the task is to determine the conjugate of this complex number.
Examples:

```Input: str = "3 - 4i"
Output: 3 + 4i

Input: str = "6 - 5i"
Output: 6 + 5i
```

Approach: A complex number is said to be a conjugate of another complex number if only the sign of the imaginary part of the two numbers is different.

```If complex number = x + iy

Conjugate of this complex number = x - iy
```

Below is the implementation of the above approach :

## C++

 `// C++ implementation to Find the``// conjugate of a complex number``#include ``using` `namespace` `std;`` ` `// Function to find conjugate``// of a complex number``void` `solve(string s)``{``    ``string z = s;``    ``int` `l = s.length();``    ``int` `i;`` ` `    ``if` `(s.find(``'+'``) < l) {`` ` `        ``// store index of '+'``        ``i = s.find(``'+'``);`` ` `        ``replace(s.begin(),``                ``s.end(),``                ``'+'``, ``'-'``);``    ``}``    ``else` `{`` ` `        ``// store index of '-'``        ``i = s.find(``'-'``);`` ` `        ``replace(s.begin(),``                ``s.end(),``                ``'-'``, ``'+'``);``    ``}`` ` `    ``// print the result``    ``cout << ``"Conjugate of "``         ``<< z << ``" = "``         ``<< s << endl;``}`` ` `// Driver code``int` `main()``{`` ` `    ``// initialise the complex number``    ``string s = ``"3-4i"``;`` ` `    ``solve(s);`` ` `    ``return` `0;``}`

## Java

 `// Java implementation to Find the``// conjugate of a complex number`` ` `class` `GFG``{``    ``// Function to find conjugate``    ``// of a complex number``    ``static` `void` `solve(String s)``    ``{``        ``String z = s;``        ``int` `l = s.length();``        ``int` `i;``        ``String str;`` ` `        ``if` `(s.indexOf(``'+'``) != -``1``) {``      ` `            ``// store index of '+'``            ``i = s.indexOf(``'+'``);``      ` `            ``str = s.replace(``'+'``, ``'-'``);``        ``}``        ``else` `{``      ` `            ``// store index of '-'``            ``i = s.indexOf(``'-'``);``      ` `            ``str = s.replace(``'-'``, ``'+'``);``        ``}``      ` `        ``// print the result``        ``System.out.println(``"Conjugate of "``             ``+ z + ``" = "``             ``+ str);``    ``}``      ` `    ``// Driver code``    ``public` `static` `void` `main(String []args)``    ``{``      ` `        ``// initialise the complex number``        ``String s = ``"3-4i"``;``      ` `        ``solve(s);``    ``}``}`` ` `// This code is contributed by chitranayal`

## Python3

 `# Python3 implementation to Find the ``# conjugate of a complex number `` ` `# Function to find conjugate ``# of a complex number ``def` `solve(s):``    ``z ``=` `s``    ``l ``=` `len``(s) ``    ``i ``=` `0``    ``if` `(s.find(``'+'``) !``=` `-``1``):``   ` `        ``# store index of '+' ``        ``i ``=` `s.find(``'+'``)``   ` `        ``s ``=` `s.replace(``'+'``, ``'-'``)``    ``else``:``        ``# store index of '-' ``        ``i ``=` `s.find(``'-'``)`` ` `        ``s ``=` `s.replace(``'-'``, ``'+'``,``1``)``   ` `    ``# print the result ``    ``print``(``"Conjugate of "``,z,``" = "``,s)`` ` ` ` `# Driver code `` ` `# initialise the complex number ``s ``=` `"3-4i"``solve(s)`` ` `# This code is contributed by Sanjit_Prasad`

## C#

 `// C# implementation to find the``// conjugate of a complex number``using` `System;`` ` `class` `GFG{``     ` `// Function to find conjugate``// of a complex number``static` `void` `solve(String s)``{``    ``String z = s;``    ``int` `l = s.Length;``    ``int` `i;``    ``String str;`` ` `    ``if` `(s.IndexOf(``'+'``) != -1) ``    ``{``         ` `        ``// Store index of '+'``        ``i = s.IndexOf(``'+'``);`` ` `        ``str = s.Replace(``'+'``, ``'-'``);``    ``}``    ``else` `    ``{`` ` `        ``// Store index of '-'``        ``i = s.IndexOf(``'-'``);`` ` `        ``str = s.Replace(``'-'``, ``'+'``);``    ``}`` ` `    ``// print the result``    ``Console.WriteLine(``"Conjugate of "``+ z +``                      ``" = "` `+ str);``}`` ` `// Driver code``public` `static` `void` `Main(String []args)``{`` ` `    ``// Initialise the complex number``    ``String s = ``"3-4i"``;`` ` `    ``solve(s);``}``}`` ` `// This code is contributed by amal kumar choubey`
Output:
```Conjugate of 3-4i = 3+4i
```

Attention reader! Don’t stop learning now. Get hold of all the important mathematical concepts for competitive programming with the Essential Maths for CP Course at a student-friendly price. To complete your preparation from learning a language to DS Algo and many more,  please refer Complete Interview Preparation Course.

My Personal Notes arrow_drop_up