高精度加减乘除模板

高精度加减法：

高精度加法

#include <iostream>
#include <vector>

using namespace std;

vector<int> add(vector<int> &A, vector<int> &B)
{
    if (A.size() < B.size()) return add(B, A);

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

    if (t) C.push_back(t);
    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 = add(A, B);

    for (int i = C.size() - 1; i >= 0; i -- ) cout << C[i];
    cout << endl;

    return 0;
}

高精度减法

//通过（t+10）%10来处理t的正负两种情况

include[HTML_REMOVED]
include[HTML_REMOVED]
using namespace std;

bool cmp(vector[HTML_REMOVED] &A,vector[HTML_REMOVED] &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[HTML_REMOVED]sub(vector[HTML_REMOVED] &A,vector[HTML_REMOVED] &B)
{
vector[HTML_REMOVED] C;
int t = 0;
for(int i = 0;i[HTML_REMOVED]1&&C.back() == 0)C.pop_back();
return C;
}
int main()
{
string a,b;
vector[HTML_REMOVED] 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’);
}
if(cmp(A,B))
{
auto C = sub(A,B);

for(int i = C.size()-1;i>=0;i--)
{
    cout<<C[i];
}
return 0;
}
else
{
    cout<<"-";
    auto C = sub(B,A); 
for(int i = C.size()-1;i>=0;i--)
{
    cout<<C[i];
}
return 0;
}
}

高精度乘法

#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;
    }

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

    return C;
}


int main()
{
    string a;
    int b;

    cin >> a >> b;

    vector<int> A;
    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;
}

高精度除法

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

using namespace std;

vector<int> div(vector<int> &A, int b, int &r)
{
    vector<int> C;
    r = 0;
    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;
    vector<int> A;

    int B;
    cin >> a >> B;
    for (int i = a.size() - 1; i >= 0; i -- ) A.push_back(a[i] - '0');

    int r;
    auto C = div(A, B, r);

    for (int i = C.size() - 1; i >= 0; i -- ) cout << C[i];

    cout << endl << r << endl;

    return 0;
}