复数乘法的问题
i的平方=-1；
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. 也挺简单的
/**
* @param {string} a
* @param {string} b
* @return {string}
*/
var complexNumberMultiply = function(a, b) {
var x=a.split("+");
var y=b.split("+");
var x1=parseInt(x[0]),x2=parseInt(x[1]),y1=parseInt(y[0]),y2=parseInt(y[1]);
var a1=(x1*y1-x2*y2)===0?'0':(x1*y1-x2*y2);
var a2="+";
var a3=(x1*y2+y1*x2)===0?'0':(x1*y2+y1*x2)
return a1+a2+a3+"i";
};
