Input Format
The overloaded operator + should receive two complex numbers ( and ) as parameters. It must return a single complex number.
The overloaded operator << should add "" to the stream where  is the real part and  is the imaginary part of the complex number which is then passed as a parameter to the overloaded operator.

# Overload Operators problem solution in c++ programming | HackerRank

//Operator Over

#include<iostream>

using namespace std;

class complex
{
public:
int a,b;
void input(string s)
{
int v1=0;
int i=0;
while(s[i]!='+')
{
v1=v1*10+s[i]-'0';
i++;
}
while(s[i]==' ' || s[i]=='+'||s[i]=='i')
{
i++;
}
int v2=0;
while(i<s.length())
{
v2=v2*10+s[i]-'0';
i++;
}
a=v1;
b=v2;
}
};

complex operator+(const complex &A, complex &B)
{
complex z;
z.a = A.a + B.a;
z.b = A.b + B.b;
return z;
}

ostream& operator<<(ostream& out, complex z)
{
out<<z.a<<"+i"<<z.b;
return out;
}
//Overload operators + and << for the class complex
//+ should add two complex numbers as (a+ib) + (c+id) = (a+c) + i(b+d)
//<< should print a complex number in the format "a+ib"
int main()
{
complex x,y;
string s1,s2;
cin>>s1;
cin>>s2;
x.input(s1);
y.input(s2);
complex z=x+y;
cout<<z<<endl;
}