以字符串形式给出的两个复数的乘法

以字符串形式给定两个复数。我们的任务是打印这两个复数的乘法。

例子：

Input : str1 = "1+1i"
        str2 = "1+1i" 
Output : "0+2i"
Here, (1 + i) * (1 + i) = 
1 + i2 + 2 * i = 2i or "0+2i"

Input : str1 = "1+-1i"
        str2 = "1+-1i"
Output : "0+-2i"
Here, (1 - i) * (1 - i) = 
1 + i2 - 2 * i = -2i or "0+-2i"

可以将两个复数相乘：
$(a+ib) \times (x+iy)=ax+i^2by+i(bx+ay)=ax-by+i(bx+ay)$

我们仅基于“ +”和“ i”符号将给定复杂字符串的实部和虚部分开。我们将两个字符串a和b的实部分别存储为x [0]和y [0] ，虚部分别存储为x [1]和y [1] 。然后，在将提取的部分转换为整数之后，根据需要将实部和虚部相乘。然后，我们再次以所需的格式形成返回字符串并返回结果。

Java

// Java program to multiply two complex numbers
// given as strings.
import java.util.*;
import java.lang.*;
 
public class GfG{
    public static String complexNumberMultiply(String a, String b) {
 
        // Spiting the real and imaginary parts
        // of the given complex strings based on '+'
        // and 'i' symbols.
        String x[] = a.split("\\+|i");
        String y[] = b.split("\\+|i");
         
        // Storing the real part of complex string a
        int a_real = Integer.parseInt(x[0]);
         
        // Storing the imaginary part of complex string a
        int a_img = Integer.parseInt(x[1]);
         
        // Storing the real part of complex string b
        int b_real = Integer.parseInt(y[0]);
         
        // Storing the imaginary part of complex string b
        int b_img = Integer.parseInt(y[1]);
         
        // Returns the product.
        return (a_real * b_real - a_img * b_img) + "+" +
              (a_real * b_img + a_img * b_real) + "i";
    }
     
    // Driver function
    public static void main(String argc[]){
        String str1 = "1+1i";
        String str2 = "1+1i";
        System.out.println(complexNumberMultiply(str1, str2));
    }
}

C++

// C++ Implementation of the above approach
#include 
using namespace std;
string complexNumberMultiply(string a, string b)
{
    int i;
    string x1;
    int temp = 1;
 
    // Traverse both strings, and
    // check for negative numbers
    for (i = 0; i < a.length(); i++)
    {
        if (a[i] == '+')
            break;
        if (a[i] == '-')
        {
            temp = -1;
            continue;
        }
        x1.push_back(a[i]);
    }
     
    // String to int
    int t1 = stoi(x1) * temp;
    x1.clear();
    temp = 1;
    for (; i < a.length() - 1; i++)
    {
        if (a[i] == '-')
        {
            temp = -1;
            continue;
        }
        x1.push_back(a[i]);
    }
    int t2 = stoi(x1) * temp;
    x1.clear();
    temp = 1;
    for (i = 0; i < b.length(); i++)
    {
        if (b[i] == '+')
            break;
        if (b[i] == '-')
        {
            temp = -1;
            continue;
        }
        x1.push_back(b[i]);
    }
    int t3 = stoi(x1) * temp;
    x1.clear();
    temp = 1;
    for (; i < b.length() - 1; i++)
    {
        if (b[i] == '-')
        {
            temp = -1;
            continue;
        }
        x1.push_back(b[i]);
    }
    int t4 = stoi(x1) * temp;
    
    // Real Part
    int ans = t1 * t3 - t2 * t4;
    string s;
    s += to_string(ans);
    s += '+';
     
    // Imaginary part
    ans = t1 * t4 + t2 * t3;
    s += to_string(ans);
    s += 'i';
 
    // Return the result
    return s;
}
 
  
// Driver Code
int main()
{
 
    string str1 = "1+1i";
    string str2 = "1+1i";
    cout << complexNumberMultiply(str1, str2);
 
    return 0;
 
    // Contributed By Bhavneet Singh
}

Python 3

# Python 3 program to multiply two complex numbers
# given as strings.
def complexNumberMultiply(a, b):
     
    # Spiting the real and imaginary parts
    # of the given complex strings based on '+'
    # and 'i' symbols.
    x = a.split('+')
    x[1] = x[1][:-1] # for removing 'i'
     
    y = b.split("+")
    y[1] = y[1][:-1] # for removing 'i'
     
    # Storing the real part of complex string a
    a_real = int(x[0])
         
    # Storing the imaginary part of complex string a
    a_img = int(x[1])
     
         
    # Storing the real part of complex string b
    b_real = int(y[0])
     
         
    # Storing the imaginary part of complex string b
    b_img = int(y[1])
    return str(a_real * b_real - a_img * b_img) \
        + "+" + str(a_real * b_img + a_img * b_real) + "i";
 
     
# Driver function
 
str1 = "1 + 1i"
str2 = "1 + 1i"
print(complexNumberMultiply(str1, str2))
 
# This code is contributed by ANKITKUMAR34

输出：

0+2i