Submission #464543

#	Time	Username	Problem	Language	Result	Execution time	Memory
464543		gesgha	Exam (eJOI20_exam)	C++17	12 / 100	1085 ms	1692 KiB

exam

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

#define fr(x, l, r) for(int x = l; x <= r; x++)
#define rf(x, l, r) for(int x = l; x >= r; x--)
#define fe(x, y) for(auto& x : y)

#define fi first
#define se second
#define m_p make_pair
#define pb push_back
#define pw(x) (ull(1) << ull(x))
#define all(x) (x).begin(),x.end()
#define sz(x) (int)x.size()
#define mt make_tuple
#define ve vector

using namespace std;
using namespace __gnu_pbds;

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
typedef pair <ll,ll> pll;
typedef pair <int,int> pii;
typedef pair <ld,ld> pld;

template<typename T>
using oset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define fbo find_by_order
#define ook order_of_key

template<typename T>
bool umn(T& a, T b) { return a > b ? a = b, 1 : 0; }
template<typename T>
bool umx(T& a, T b) { return a < b ? a = b, 1 : 0; }

const ll inf = 1e18;
const int intf = 1e9;
const ll mod = 1e9 + 7;
const ld eps = 0.00000001;
const ll N  = 1e5 + 5;

int a[N], b[N], B, f[N], n, dp[N], ans;

queue <ll> q;

void add(int pos, int& ans){
    if(pos < 0 || pos >= n || f[pos] || a[pos] > B)return;
    ans++;
    f[pos] = 1;
    q.push(pos);
}

void rec(int nom){

    int cnt = 0;
    fr(i, 0, n - 1){
        cnt += bool(a[i] == b[i]);
    }
    ans = max(ans, cnt);
    fr(i, nom, n - 1){
        int c = a[i], d = a[i + 1];
        if(i < n - 1 && c != d){
            a[i] = max(a[i], a[i + 1]);
            a[i + 1] = max(a[i], a[i + 1]);
            rec(i + 1);
            a[i] = c;
            a[i + 1] = d;
            rec(i + 1);
        }
    }
}

int main(){

#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt","w", stdout);
    ios_base::sync_with_stdio(0);
    cin.tie(0);
#else
//    freopen("mountains.in", "r", stdin);
//    freopen("mountains.out","w", stdout);
    ios_base::sync_with_stdio(0);
    cin.tie(0);
#endif
    cin >> n;

    fr(i, 0, n - 1){
        cin >> a[i];
    }
    bool ff = 0;
    fr(i, 0, n - 1){
        cin >> b[i];
        if(i && b[i] != b[i - 1]){
            ff = 1;
        }
    }
    if(!ff){
        int  ans = 0;
        B = b[0];
        fr(i, 0, n - 1){
            if(a[i] == B){
                q.push(i);
                f[i] = 1;
                ans++;
            }
        }

        while(!q.empty()){
            int p = q.front();
            add(p + 1, ans);
            add(p - 1, ans);
            q.pop();
        }
        cout << ans << endl;
    }
    else{
        rec(0);
        cout << ans << endl;
    }

    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