高精度的加法

vector<int> add(vector<int>&A,vector<int>&B)
{
    vector<int>C;
    int t=0;
    for(int i=0;i<A.size()||i<B.size();i++)
    {
        if(i<A.size())t+=A[i];
        if(i<B.size())t+=B[i];
        C.push_back(t%10);
        t/=10;
    }
    if(t)C.push_back(1);
    return C;
}

高精度的减法

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

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

高精度乘法

vector<int> mul(vector<int>&A,int b)
{
    vector<int>C;
    int t=0;

    for(int i=0;i<A.size();i++)
    {
        t+=A[i]*b;
        C.push_back(t%10);
        t/=10;

    }

    while(t)C.push_back(t%10),t/=10;
    while(C.size()>1&&C.back()==0)C.pop_back();
    return C;
}

高精度除法

vector<int> div(vector<int>&A,int B,int &r)
{
    vector<int>C;
    for(int i=A.size()-1;i>=0;i--)
    {
        r=r*10+A[i];
        C.push_back(r/B);
        r%=B;
    }
    reverse(C.begin(),C.end());
    while(C.size()>1&&C.back()==0)C.pop_back();
    return C;
}