跳转至

High precision calc

高精度加法

C++
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
#include <bits/stdc++.h>
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.length() - 1; i >= 0; i--) A.push_back(a[i] - '0');
    for (int i = b.length() - 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;
}

高精度减法

C++
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
#include <bits/stdc++.h>
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;
    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, B;
    cin >> a >> b;
    for (int i = a.length() - 1; i >= 0; i--) A.push_back(a[i] - '0');
    for (int i = b.length() - 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--) cout << C[i];
    cout << endl;
}

高精度乘法

C++
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
// 高精 a * 低精 b
#include <bits/stdc++.h>
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;
    vector<int> A;
    cin >> a >> b;
    for (int i = a.length() - 1; i >= 0; i--) A.push_back(a[i] - '0');
    auto C = mul(A, b);
    for (int i = C.size() - 1; i >= 0; i--) cout << C[i];
    cout << endl;
}

高精度除法

C++
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
#include <bits/stdc++.h>
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;
    int b;
    vector<int> A;
    cin >> a >> b;
    for (int i = a.size(); 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; // r 为余数
}