0043-multiply-strings.adoc

43. Multiply Strings

{leetcode}/problems/multiply-strings/[LeetCode - 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:

1. The length of both num1 and num2 is < 110.

2. Both num1 and num2 contain only digits 0-9.

3. Both num1 and num2 do not contain any leading zero, except the number 0 itself.

4. You must not use any built-in BigInteger library or convert the inputs to integer directly.

解题思路

将每次相乘的计算结果存入到一个数组中，每个元素保存一个位上的数字。

参考资料

1. 优化版竖式(打败99.4%) - 字符串相乘 - 力扣（LeetCode） — 第二种解法，最初没看明白，但是受他们的启发，我自己想到了。

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:

1. The length of both num1 and num2 is < 110.

2. Both num1 and num2 contain only digits 0-9.

3. Both num1 and num2 do not contain any leading zero, except the number 0 itself.

4. You must not use any built-in BigInteger library or convert the inputs to integer directly.

link:{sourcedir}/_0043_MultiplyStrings.java[role=include]