C++ 代码

#include <iostream>
#include <vector>
#include <cstdio>
#include <string>

using namespace std;

vector<int> sub(vector<int> &A, vector<int> &B)
{
    vector<int> C;

    int t = 0;
    for (int i = 0; i < A.size(); i ++)
    {
        t = A[i] - t;
        if (i < B.size()) t -= B[i];
        C.push_back((t + 10) % 10);
        if (t < 0) t = 1;
        else t = 0;
    }
    return C;
}

int main()
{
    string a, b;
    vector<int> A, B;
    cin >> a >> b;
    for (int i = a.size() - 1; i >= 0; i -- ) A.push_back(a[i] - '0');
    for (int i = b.size() - 1; i >= 0; i -- ) B.push_back(b[i] - '0');
    auto C = sub(A, B);
    for (int i = C.size() - 1; i >= 0; i -- ) printf("%d", C[i]);
    return 0;
}