leetcode537. Complex Number Multiplication

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:

1. The input strings will not have extra blank.

1. 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.

这道题其实看起来就很简单，所以也采用了很简单的方式，代码看起来写的也很烂。

    public static String complexNumberMultiply(String a, String b) {        String[] a1 = a.split("\\+");        String[] b1 = b.split("\\+");        int temp1,temp2,temp3;        temp1 = Integer.valueOf(a1[0])*Integer.valueOf(b1[0]);        temp2 = Integer.valueOf(a1[1].replace("i", ""))*Integer.valueOf(b1[1].replace("i",""));        temp3 = Integer.valueOf(a1[0])*Integer.valueOf(b1[1].replace("i",""))+Integer.valueOf(a1[1].replace("i", ""))*Integer.valueOf(b1[0]);        int cur = temp1 - temp2;        String res = Integer.toString(cur) +"+"+ temp3+"i";        return res;    }