高精度

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高精度算法 四则运算模板

Add

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#include <iostream>
#include <vector>

using namespace std;

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;
}

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

Subtract

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#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();
    else
    {
        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;
    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;
}

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

Divide

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#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

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;
}

int main()
{
    string a;
    int b, r = 0;
    vector<int> A;
    cin >> a >> b;
    for (int i = a.size() - 1; i >= 0; i--)
        A.push\_back(a\[i\] - '0');
    auto C = div(A, b, r);
    for (int i = C.size() - 1; i >= 0; i--)
        printf("%d", C\[i\]);
    cout << endl << r << endl;
    return 0;
}

Multiply

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#include <iostream>
#include <vector>

using namespace std;

vector<int> mul(vector<int> &A, int &b)
{
    vector<int> C;
    int t = 0;
    for (int i = 0; i < A.size()  t; i++)
    {
        if (i < A.size())
            t += A\[i\] \* b;
        C.push\_back(t % 10);
        t /= 10;
    }
    return C;
}
int main()
{
    string a;
    vector<int> A;
    int b;
    cin >> a >> b;
    for (int i = a.size() - 1; i >= 0; i--)
        A.push\_back(a\[i\] - '0');
    auto C = mul(A, b);
    for (int i = C.size() - 1; i >= 0; i--)
        printf("%d", C\[i\]);
    return 0;
}