Given two numbers represented as strings, return multiplication of the numbers as a string.
Note: The numbers can be arbitrarily large and are non-negative.
题目当中主要是需要两个大数的乘法，一般大数都是用字符串进行保存
代码比较简单，主要是利用了一个vector反向的存储了计算的结果，然后reverse到string当中进行输出
这里当然可以直接定义一个string然后其中进行操作，，那么就会出现很多char和int之间的转换，感觉比较麻烦
class Solution {public:string multiply(string num1, string num2) {if(num1=="0" || num2=="0") return "0";int length1 = num1.size();int length2 = num2.size();vector<int> mulResult(length1+length2,0);//<used to restore the multi resultint i = 0,j = 0;int temp = 0;int nextNum = 0; //<10位数int index = 0;int n1;int n2;for(i = length2-1; i >= 0; i–){index = (length2-1)-i;n2 = num2[i]-'0';nextNum = 0;for(j = length1-1; j >= 0;j–){n1 = num1[j]-'0';temp = n2*n1;temp += nextNum; //<加上上一次进位的数temp += mulResult[index]; //<加上之前计算的结果mulResult[index] = (temp%10);nextNum = temp/10;index++;}if(nextNum>0){mulResult[index] = nextNum;index++;}}string result = "";for(i = index-1; i>=0;i–){result += ('0'+ mulResult[i]);}return result;}};
在这个阳光明媚的三月，我从我单薄的青春里打马而过，
