Given two non-negative integers num1 and num2 represented as strings, return the product of the two numbers, also as a string. This problem tests manual digit handling and carry propagation for large values.
num1 and num2 = non-negative integer strings
product as a decimal string
Example 1:
Input:
num1 = "2" num2 = "3"
Output:
6
Explanation:
2 × 3 = 6.
Example 2:
Input:
num1 = "123" num2 = "456"
Output:
56088
Explanation:
123 × 456 = 56088.