小杨编写了一个如下的高精度减法函数： 下面说法，正确的是（ ）。

vector<int> highPrecisionSubtract(vector<int> a, vector<int> b) {
    vector<int> result;
    int borrow = 0;

    for (int i = 0; i < a.size(); ++i) {
        int digitA = a[i];
        int digitB = i < b.size() ? b[i] : 0;

        int diff = digitA - digitB - borrow;
        if (diff < 0) {
            diff += 10;
            borrow = 1;
        }
        else {
            borrow = 0;
        }

        result.push_back(diff);
    }

    while (result.size() > 1 && result.back() == 0) {
        result.pop_back();
    }

    return result;
}