LeetCode Multiply Strings
发布时间：2020-12-13 20:04:38 所属栏目：PHP教程 来源：网络整理
导读：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. 题意：字符串的乘法。 思路：摹拟竖乘的思路，跟大数计算1样，先将字符串颠倒 class Solu
|
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. 题意：字符串的乘法。思路：摹拟竖乘的思路，跟大数计算1样，先将字符串颠倒 class Solution {
public:
string multiply(string num1,string num2) {
reverse(num1.begin(),num1.end());
reverse(num2.begin(),num2.end());
int len1 = num1.size(),len2 = num2.size();
string ans(len1+len2+1,'0');
int tmp = 0;
for (int i = 0; i < len1; i++) {
int cur = num1[i] - '0';
tmp = 0;
for (int j = 0; j < len2; j++) {
int a = tmp + cur * (num2[j]-'0') + (ans[i+j]-'0');
tmp = a / 10;
ans[i+j] = a % 10 + '0';
}
int idx = len2;
while (tmp != 0) {
int a = tmp + (ans[i+idx]-'0');
tmp = a / 10;
ans[i+idx] = a % 10 + '0';
idx++;
}
}
while (!ans.empty() && ans.back() == '0')
ans.pop_back();
if (ans.empty()) return "0";
reverse(ans.begin(),ans.end());
return ans;
}
};
（编辑：李大同） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |