标签：res als == tor rect ack bsp note span
https://leetcode.com/problems/multiply-strings/
Given two non-negative integers num1 and num2 represented as strings, return the product of num1 and num2, also represented as a string.
Example 1:
Input: num1 = "2", num2 = "3" Output: "6"
Example 2:
Input: num1 = "123", num2 = "456" Output: "56088"
Note:
num1 and num2 is < 110.num1 and num2 contain only digits 0-9.num1 and num2 do not contain any leading zero, except the number 0 itself.代码：
class Solution {
public:
string multiply(string num1, string num2) {
string res;
int n1 = num1.size(), n2 = num2.size();
int k = n1 + n2 - 2, carry = 0;
vector<int> v(n1 + n2, 0);
for (int i = 0; i < n1; ++i) {
for (int j = 0; j < n2; ++j)
v[k - i - j] += (num1[i] - ‘0‘) * (num2[j] - ‘0‘);
}
for (int i = 0; i < n1 + n2; ++i) {
v[i] += carry;
carry = v[i] / 10;
v[i] %= 10;
}
int i = n1 + n2 - 1;
while (v[i] == 0) --i;
if (i < 0) return "0";
while (i >= 0) res.push_back(v[i--] + ‘0‘);
return res;
}
};
大数乘法
#Leetcode# 43. Multiply Strings
标签：res als == tor rect ack bsp note span
原文地址：https://www.cnblogs.com/zlrrrr/p/10009257.html
