【LeetCode】Multiply Strings

参考链接

http://blog.csdn.net/pickless/article/details/9235907

http://blog.csdn.net/doc_sgl/article/details/13279999

题目描述

Multiply Strings

 Total Accepted: 7579 Total Submissions: 37951My Submissions

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.

题目分析

总结

代码示例

string multiply(string num1, string num2) {if(num1=="0" || num2=="0") return "0";int l1 = num1.length(), l2 = num2.length();int* n1 = new int[l1];int* n2 = new int[l2];int* res = new int[l1+l2];memset(res,0,sizeof(int)*(l1+l2));for(int i=0; i<l1; ++i)n1[i] = num1[i] - '0';for(int i=0; i<l2; ++i)n2[i] = num2[i] - '0';for(int i=0; i<l1; ++i)for (int j=0; j<l2; ++j)res[i+j+1] += n1[i]*n2[j];string ss = "";for (int k=l1+l2-1; k>=0; --k){if(k>0) res[k-1] += res[k]/10;res[k] %= 10;ss = char(res[k]+'0')+ss;}ss = ss[0]=='0'? ss.substr(1):ss;//return ss.empty()?"0":ss;return ss;}

推荐学习C++的资料

C++标准函数库

http://download.csdn.net/detail/chinasnowwolf/7108919

在线C++API查询

http://www.cplusplus.com/