P1045 60分超时求助

#include<bits/stdc++.h>
using namespace std;
int n,a[501];
long long s;
int main ()
{
    cin>>n;
    a[1]=1;
    s=log10(2)*n+1;
    for (int i=1;i<=n;i++)
    {
        int jw=0;
        for (int j=1;j<=500;j++)
        {
            a[j]=a[j]*2+jw;
            jw=a[j]/10;
            a[j]%=10;
        }
    }
    a[1]--;
    int k=1;
    while (a[k]<0)
    {
        a[k+1]--;
        a[k]+=10;
        k++;
    }
    cout<<s<<endl;
    for (int i=500;i>=1;i--)
    {
        cout<<a[i];
        if (i%50==1) cout<<endl;
    }
    return 0;
}