Submission #433032

#	Time	Username	Problem	Language	Result	Execution time	Memory
433032		Valaki2	Exam (eJOI20_exam)	C++14	12 / 100	29 ms	1492 KiB

exam

#include <bits/stdc++.h>
using namespace std;

int n;
vector<int> a;
vector<int> b;

void solve_bf() {
    
}

void solve_bequal() {
    int x = b[1];
    int last = 0;
    bool ok = false;
    int ans = 0;
    a.push_back(x + 1);
    for(int i = 1; i <= (n + 1); ++i) {
        if(a[i] > x) {
            if(ok) {
                ans += i - last - 1;
                ok = false;
            }
            last = i;
        } else if(a[i] == x) {
            ok = true;
        }
    }
    cout << ans << "\n";
}

void solve_astrictlyincreasing() {
    vector<int> dp(1 + n, 0);
    vector<bool> ok(1 + n, false);
    for(int i = 1; i <= n; ++i) {
        dp[i] = dp[i - 1];
        if(a[i] == b[i]) {
            ++dp[i];
            ok[i] = true;
        }
        int cur = dp[i];
        int l = i;
        for(int j = i - 1; j >= 1; --j) {
            if(ok[j]) --cur;
            if(a[i] == b[j]) ++cur;
            if(cur > dp[i]) {
                dp[i] = cur;
                l = j;
            }
        }
        for(int j = i - 1; j >= l; --j) {
            if(a[i] == b[j]) ok[j] = true;
            else ok[j] = false;
        }
    }
    cout << dp[n] << "\n";
}

void solve() {
    cin >> n;
    a.assign(1 + n, 0);
    b.assign(1 + n, 0);
    for(int i = 1; i <= n; ++i) cin >> a[i];
    for(int i = 1; i <= n; ++i) cin >> b[i];
    set<int> b_set;
    for(int i = 1; i <= n; ++i) {
        b_set.insert(b[i]);
    }
    /*if(n <= 10) {
        solve_bf();
    } else */if(b_set.size() == 1) {
        solve_bequal();
    } else {
        solve_astrictlyincreasing();
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    solve();
    return 0;
}

• Subtask 1: 0 / 14
• Subtask 2: 12 / 12
• Subtask 3: 0 / 13
• Subtask 4: 0 / 23
• Subtask 5: 0 / 16
• Subtask 6: 0 / 22