求最长公共子序列的路径,从后到前输出

#include<iostream>
using namespace std;
const int N = 505;
int n;
int a[N],f[N],g[N];
int main()
{
    cin>>n;
    for(int i = 1;i <= n;i++) cin>>a[i];
    for(int i = 1;i <= n;i++)
    {
        f[i] = 1;
        g[i] = 0;
        for(int j = 1;j < i;j++)
        {
            if(a[j] < a[i])
            {
                if(f[i] < f[j]+1)
                    {
                        f[i] = f[j]+1;
                        g[i] = j;
                    }
            }
        }
    }
    int k = 1;
    for(int i = 1;i <= n;i++)
        if(f[k]<f[i]) k = i;
    cout<<f[k]<<endl;
    for(int i = 0,len = f[k];i < len;i++)
    {
        cout<<a[k]<<" ";
        k = g[k];
    }
    return 0;
}