Given two strings representing two complex numbers.
You need to return a string representing their multiplication. Note i2 = -1 according to the definition.
Example 1:
Input: "1+1i", "1+1i" Output: "0+2i" Explanation: (1 + i) * (1 + i) = 1 + i2 + 2 * i = 2i, and you need convert it to the form of 0+2i.
Example 2:
Input: "1+-1i", "1+-1i" Output: "0+-2i" Explanation: (1 - i) * (1 - i) = 1 + i2 - 2 * i = -2i, and you need convert it to the form of 0+-2i.
Note:
- The input strings will not have extra blank.
- The input strings will be given in the form of a+bi, where the integer a and b will both belong to the range of [-100, 100]. And the output should be also in this form.
1 public class Solution { 2 public String complexNumberMultiply(String a, String b) { 3 String[] A = a.split("\+"); 4 int a1 = Integer.parseInt(A[0]); 5 int b1 = Integer.parseInt(A[1].replace("i", "")); 6 7 String[] B = b.split("\+"); 8 int a2 = Integer.parseInt(B[0]); 9 int b2 = Integer.parseInt(B[1].replace("i", "")); 10 11 int newA = a1 * a2 - b1 * b2; 12 int newB = a1 * b2 + b1 * a2; 13 return newA + "+" + newB + "i"; 14 } 15 }