Submission #835419

#	Time	Username	Problem	Language	Result	Execution time	Memory
835419		otarius	Exam (eJOI20_exam)	C++17	100 / 100	70 ms	8836 KiB

exam

#include <iostream>
#include <algorithm>
#include <vector>
#include <set>
#include <cstring>
#include <queue>
#include <map>
#include <cmath>
#include <iomanip>
#include <stack>
using namespace std;

#define ff first
#define sc second
#define pb push_back
#define ll long long
#define pll pair<ll, ll>
#define pii pair <int, int>
#define ull unsigned long long

// #define int long long
// #define int unsigned long long

const ll inf = 1e9 + 7;
const ll weirdMod = 998244353;

void solve() {
    int n;
    cin >> n;
    int seg[n + 1][2];
    for (int i = 0; i <= n; i++)
        seg[i][0] = seg[i][1] = -1;
    vector<int> a(n);
    vector<int> b(n);
    for (int &v : a) cin >> v;
    for (int &v : b) cin >> v;
    map<int, int> cont; stack<int> st;
    for (int i = 0; i < n; i++) {
        while (!st.empty() && st.top() <= a[i]) {
            cont.erase(st.top()); st.pop();
        } cont[a[i]] = i; st.push(a[i]);
        if (cont.find(b[i]) != cont.end())
            seg[i][0] = cont[b[i]];
    } cont.clear(); while (!st.empty()) st.pop();
    for (int i = n - 1; i >= 0; i--) {
        while (!st.empty() && st.top() <= a[i]) {
            cont.erase(st.top()); st.pop();
        } cont[a[i]] = i; st.push(a[i]);
        if (cont.find(b[i]) != cont.end())
            seg[i][1] = cont[b[i]];
    } vector<int> vec, lis;
    for (int i = 0; i < n; i++) {
        if (seg[i][1] != -1) vec.pb(seg[i][1]);
        if (seg[i][0] != -1 && seg[i][0] != seg[i][1]) vec.pb(seg[i][0]);
    } for (int v : vec) {
        auto it = upper_bound(lis.begin(), lis.end(), v);
        if (it == lis.end()) lis.pb(v);
        else *it = v;
    } cout << lis.size();
}
int32_t main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);
    
    int t = 1;
    // cin >> t;
    while (t--) {
        solve();
        cout << '\n';
    }
    return 0;
}

• Subtask 1: 14 / 14
• Subtask 2: 12 / 12
• Subtask 3: 13 / 13
• Subtask 4: 23 / 23
• Subtask 5: 16 / 16
• Subtask 6: 22 / 22