记录路径的写法
#include <iostream>
#include <algorithm>
using namespace std;
const int N = 100010;
int n;
int a[N];
int q[N];
int pre[N];
int main()
{
scanf("%d", &n);
for (int i = 0; i < n; i ++ ) scanf("%d", &a[i]);
int len = 0;
for (int i = 0; i < n; i ++ )
{
int l = 0, r = len;
while (l < r)
{
int mid = l + r + 1 >> 1;
if (a[q[mid]]< a[i]) l = mid;
else r = mid - 1;
}
len = max(len, r + 1);
q[r + 1] = i;
pre[i] = q[r];
}
printf("%d\n", len);
int x = q[len];
while (x)
{
cout << a[x] << ' ';
x = pre[x];
}
return 0;
}