Program to Add Two Complex Numbers in C

Given are the two complex numbers in the form of a1+ ib1 and a2 + ib2, the task is to add these two complex numbers.

Complex numbers are those numbers which can be expressed in the form of “a+ib” where “a” and “b” are the real numbers and i is the imaginary number which is the solution of the expression 𝑥 2 = −1 as no real number satisfies the equation that’s why it is called as imaginary number.

Input 

a1 = 3, b1 = 8
a2 = 5, b2 = 2

Output 

Complex number 1: 3 + i8
Complex number 2: 5 + i2
Sum of the complex numbers: 8 + i10

Explanation 

(3+i8) + (5+i2) = (3+5) + i(8+2) = 8 + i10

Input 

a1 = 5, b1 = 3
a2 = 2, b2 = 2

Output 

Complex number 1: 5 + i3
Complex number 2: 2 + i2
Sum of the complex numbers: 7 + i5

Explanation 

(5+i3) + (2+i2) = (5+2) + i(3+2) = 7 + i5

Approach used below is as follows to solve the problem

• Declare a struct for storing the real and imaginary numbers.

• Take the input and add the real numbers and imaginary numbers of all the complex numbers.

Algorithm

Start
Decalre a struct complexnum with following elements
   1. real
   2. img
In function complexnum sumcomplex(complexnum a, complexnum b)
   Step 1→ Declare a signature struct complexnum c
   Step 2→ Set c.real as a.real + b.real
   Step 3→ Set c.img as a.img + b.img
   Step 4→ Return c
In function int main()
   Step 1→ Declare and initialize complexnum a = {1, 2} and b = {4, 5}
   Step 2→ Declare and set complexnum c as sumcomplex(a, b)
   Step 3→ Print the first complex number
   Step 4→ Print the second complex number
   Step 5→ Print the sum of both in c.real, c.img
Stop

Example

#include <stdio.h>
//structure for storing the real and imaginery
//values of complex number
struct complexnum{
   int real, img;
};
complexnum sumcomplex(complexnum a, complexnum b){
   struct complexnum c;
   //Adding up two complex numbers
   c.real = a.real + b.real;
   c.img = a.img + b.img;
   return c;
}
int main(){
   struct complexnum a = {1, 2};
   struct complexnum b = {4, 5};
   struct complexnum c = sumcomplex(a, b);
   printf("Complex number 1: %d + i%d
", a.real, a.img);
   printf("Complex number 2: %d + i%d
", b.real, b.img);
   printf("Sum of the complex numbers: %d + i%d
", c.real, c.img);
   return 0;
}

Output

If run the above code it will generate the following output −

Complex number 1: 1 + i2
Complex number 2: 4 + i5
Sum of the complex numbers: 5 + i7