题解 | #进制转换#

自创的大数进制转换模板，效率不高，但是比较容易懂。

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

vector<int> bas_change(vector<int> A, int ob, int nb)
{
    vector<int> C;                    //商
    vector<int> D;                    //转换后的结果
    if (A.size() == 1 && A[0] == 0) //0直接返回
        return {0};
    while (A[0] != 0 || A.size() > 1) //当除成0的时候退出
    {
        int r = 0;
        for (int i = A.size() - 1; i >= 0; --i)
        {
            r = r * ob + A[i];
            C.push_back(r / nb);
            r %= nb;
        }
        reverse(C.begin(), C.end());
        while (C.size() > 1 && C.back() == 0) //去除前导0
            C.pop_back();

        A = C;
        C.clear();
        D.push_back(r);
    }
    return D;
}

int main()
{
    string a;
    while (cin >> a)
    {
        vector<int> b;
        for (int i = a.size() - 1; i >= 0; --i)
            b.push_back(a[i] - '0');
        auto res = bas_change(b, 10, 2);
        for (int i = res.size()- 1; i >= 0; --i)
            cout << res[i];
        cout << endl;
    }
    return 0;
}