在对数组中存储的大数进行相加时，如何确保正确的进位传播？

struct Adder {
  // Array to store the digits
  unsigned short digits[n];
  // Flag to handle carry
  unsigned short carry;

  // Constructor to initialize the adder
  Adder() {
    for (int i = 0; i < n; i++) {
      digits[i] = 0;
    }
    carry = 0;
  }

  // Function to add two digits with carry propagation
  void addWithCarry(unsigned short a, unsigned short b) {
    unsigned short sum = a + b + carry;
    digits[i] = sum % 10; // Store the last digit (0-9)
    carry = sum / 10;      // Carry for the next digit
  }

  // Function to perform addition on the entire array
  void add(const Adder& rhs) {
    for (int i = 0; i < n; i++) {
      addWithCarry(digits[i], rhs.digits[i]);
    }
  }
};