leetcode 537. Complex Number Multiplication C++中的stringstream真的很好用

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.

本题意很简单，就是计算复数的乘法，

这道题最大的启发就是C++的stringstream真的很好用

建议和这一道题leetcode 539. Minimum Time Difference C++中的stringstream真的很好用 一起学习

代码如下：

#include <iostream>#include <vector>#include <map>#include <set>#include <queue>#include <stack>#include <string>#include <climits>#include <algorithm>#include <sstream>#include <functional>#include <bitset>#include <numeric>#include <cmath>using namespace std;class Solution{public:    string complexNumberMultiply(string a, string b)     {        int ra, ia, rb, ib;        char buff;        stringstream aa(a), bb(b), ans;        aa >> ra >> buff >> ia >> buff;        bb >> rb >> buff >> ib >> buff;        ans << ra*rb - ia*ib << "+" << ra*ib + rb*ia << "i";        return ans.str();    }};