十行求解 $O(n \log n)$ 求最长上升子序列

#include <bits/stdc++.h>
int n, x, f[100001];
int main() {
    memset(f, 63, sizeof(f));
    scanf("%d", &n);
    for (int i = 1; i <= n; i++)
        scanf("%d", &x), *std::lower_bound(f + 1, f + n + 1, x) = x;
    printf("%d\n", std::lower_bound(f + 1, f + n + 1, f[0]) - f - 1);
    return 0;
}