如何在C++中实现两个4位数的乘法运算

#include <iostream>

int main() {
    int num1 = 1234;
    int num2 = 5678;
    int result = 0;

    for (int i = 0; i < 4; i++) {
        int carry = 0;
        for (int j = 0; j < 4; j++) {
            int digit1 = (num1 / static_cast<int>(pow(10, i))) % 10;
            int digit2 = (num2 / static_cast<int>(pow(10, j))) % 10;
            int product = digit1 * digit2 + carry;
            carry = product / 10;
            result += (product % 10) * static_cast<int>(pow(10, i + j));
        }
        result += carry * static_cast<int>(pow(10, i + 4));
    }

    std::cout << "Multiplication result: " << result << std::endl;

    return 0;
}