求助，错第10个点

#include<iostream>

using namespace std;

int gj[1001] = { 1 }, last[1001] = { 2 }, len = 1;

int main( ) {

    int n; cin >> n;

    if ( n == 1 ) {
        cout << 1;
        return 0;
    } if ( n == 2 ) {
        cout << 2;
        return 0;
    }

    for ( int i = 3; i <= n; i++ ) {
        for ( int j = 0; j < len; j++ )
            gj[j] += last[j], gj[j+1] += gj[j] / 10, gj[j] %= 10;
        if ( gj[len] )
            len++;

        swap( gj, last );
    }

    for ( int i = len - 1; i >= 0; i-- )
        cout << last[i];

    return 0;

}