C++高精加法计算斐波那契数列，100（仅供参考）

#include<iostream>
#include<vector>
#include<string>
using namespace std;
int main()
{
    int n;
    vector<vector<char>> a(5001);
    cin >> n;
    a[0].push_back('0');
    a[1].push_back('1');
    a[2].push_back('2');
    int nn, t = 0;
    string temp;
    for (int i = 2; i < n; i++)
    {
        nn = a[i].size() > a[i - 1].size() ? a[i].size() : a[i - 1].size();
        for (int j = 0; j <= nn; j++)
        {
            if (j == nn && t == 0)
                break;
            if (j < a[i - 1].size() && j < a[i].size())
                t += a[i - 1][j] + a[i][j] - '0';
            if (j >= a[i - 1].size() && j < a[i].size())
                t += a[i][j];
            if (j < a[i - 1].size() && j >= a[i].size())
                t += a[i - 1][j];
            if (j >= a[i - 1].size() && j >= a[i].size())
                t += '0';
            a[i + 1].push_back((t - '0') % 10 + '0');
            t = (t - '0') / 10;
        }
    }
    for(int j=0;j<a[n].size();j++)
        cout << a[n][a[n].size()-j-1];
    return 0;
}