45 lines
1.0 KiB
C++
45 lines
1.0 KiB
C++
#include <bits/stdc++.h>
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using namespace std;
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/**
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* 功能：高精度乘高精度模板
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* @param A
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* @param b
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* @return
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*/
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vector<int> mul(vector<int> &A, vector<int> &B) {
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//初始化大小
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vector<int> C(A.size() + B.size());
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//先放里再说
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for (int i = 0; i < A.size(); i++)
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for (int j = 0; j < B.size(); j++)
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C[i + j] += A[i] * B[j];
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//处理余数
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for (int i = 0, t = 0; i < C.size(); i++) {
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t += C[i];
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if (i >= C.size()) C.push_back(t % 10);
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else C[i] = t % 10;
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t /= 10;
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}
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//去掉前导0
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while (C.size() > 1 && C.back() == 0) C.pop_back();
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return C;
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}
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int main() {
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string a, b;
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cin >> a >> b;
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//准备动作
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vector<int> A, B;
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for (int i = a.size() - 1; i >= 0; i--) A.push_back(a[i] - '0');
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for (int i = b.size() - 1; i >= 0; i--) B.push_back(b[i] - '0');
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//计算
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vector<int> C = mul(A, B);
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//倒序输出
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for (int i = C.size() - 1; i >= 0; i--) cout << C[i];
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return 0;
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}
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