P1020 [NOIP1999 普及组] 导弹拦截(最长上升/不升子序列)

[NOIP1999 普及组] 导弹拦截 - 洛谷https://www.luogu.com.cn/problem/P1020

#include <iostream>
#include <cstdio>
#include <string>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <cstring>
#include <set>
#include <cmath>
#include <map>
#include <cstdlib>
typedef long long ll;
typedef unsigned long long ull;
using namespace std;
const int MN = 65005;
const int MAXN = 2000010;
const int INF = 0x3f3f3f3f;
#define IOS ios::sync_with_stdio(false)


int a[MAXN], d1[MAXN], d2[MAXN], n;
int len1, len2;
int main() {
	while (scanf("%d", &a[++n]) != EOF) {
	}
	n--;
	d1[++len1] = a[1];
	d2[++len2] = a[1];
	for (int i = 2; i <= n; i++) {
		if (d1[len1] >= a[i]) {
			d1[++len1] = a[i];
		} else {
			*upper_bound(d1 + 1, d1 + len1 + 1, a[i], greater<int>()) = a[i];
		}
		if (d2[len2] < a[i]) {
			d2[++len2] = a[i];
		} else {
			*lower_bound(d2 + 1, d2 + len2 + 1, a[i]) = a[i];
		}
	}
	printf("%d\n%d", len1, len2);
	return 0;
}