miao~~~

算法1

C++ 代码

#include<iostream>
#include<vector>

using namespace std;

bool cmp(vector<int> &A,vector<int> &B)
{
    if (A.size() != B.size()) return A.size() > B.size();

    for (int i=A.size()-1;i >= 0; i --)
    {
        if (A[i] != B[i]) return A[i] > B[i];
    }
    return true;
}

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

    for (int i=0,t=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;
    }

    while (C.size()>1 && C.back()==0) C.pop_back();

    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');

    vector<int> C;
    if (cmp(A,B)) C=sub(A,B);
    else C=sub(B,A),cout << '-';

    for (int i=C.size()-1;i>=0;--i) printf("%d",C[i]);
    cout << endl;
    return 0;

}