Submission #1288253

#	Time	Username	Problem	Language	Result	Execution time	Memory
1288253		nguyn	Sequence (APIO23_sequence)	C++20	Compilation error	0 ms	0 KiB

sequence

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

#ifdef LOCAL
#include "debug.h"
#else
#define debug(...)
#endif // LOCAL

#define ll long long 
#define F first
#define S second
#define pb push_back
#define pii pair<int, int>

const int inf = 1e9; 

vector<int> a;
vector<vector<int>> pos; 

struct Node {
    int mn, mx;    

    Node() {}
    Node(int mn, int mx) : mn(mn), mx(mx) {}

    Node operator + (const Node& o) {
        Node res; 
        res.mn = min(o.mn, mn); 
        res.mx = max(o.mx, mx); 
        return res; 
    }

    Node operator + (int x) {
        Node res;
        res.mn += x;
        res.mx += x;
        return res;
    }

    friend ostream& operator<<(ostream& os, Node p) {
		return os << "(" << p.mn << "," << p.mx << ")"; }
}; 

struct SegTree {

    int n; 
    vector<Node> st;
    vector<int> lazy; 

    SegTree() {}
    SegTree(int n) : n(n) {
        st.resize(4 * n + 5);
        lazy.resize(4 * n + 5);   
    }

    void build(int id, int l, int r) {
        if (l == r) { 
            st[id].mn = l;
            st[id].mx = l; 
            return;
        }
        int mid = (l + r) / 2;
        build(id * 2, l, mid);
        build(id * 2 + 1, mid + 1, r); 
        st[id] = st[id * 2] + st[id * 2 + 1]; 
    }

    void update(int id, int l, int r, int u, int v, int x) {
        if (u > r || v < l) return;
        if (u <= l && r <= v) {
            st[id].mn += x;
            st[id].mx += x;
            lazy[id] += x; 
            return;
        }
        int mid = (l + r) / 2;
        update(id * 2, l, mid, u, v, x);
        update(id * 2 + 1, mid + 1, r, u, v, x);
        st[id] = (st[id * 2] + st[id * 2 + 1]) + lazy[id]; 
    }

    Node get(int id, int l, int r, int u, int v) {
        if (l > v || r < u) return Node(inf, - inf); 
        if (u <= l && r <= v) return st[id];
        int mid = (l + r) / 2;
        return (get(id * 2, l, mid, u, v) + get(id * 2 + 1, mid + 1, r, u, v)) + lazy[id];
    }
} st; 


int sequence(int N, vector<int> A) {
    int n = N; 
    assert(a.empty()); 
    a.resize(n + 3); 
    pos.resize(n + 3); 
    for (int i = 1; i <= n; i++) {
        a[i] = A[i - 1]; 
        pos[a[i]].pb(i); 
    }
    st = SegTree(n);
    st.build(1, 0, n); 
    int res = 0; 
    for (int i = 1; i <= n; i++) {
        // debug(pos[i]); 
        vector<Node> l1, l2, r1, r2; 
        for (int j : pos[i]) {
            l1.pb(st.get(1, 0, n, 0, j - 1));
            r1.pb(st.get(1, 0, n, j, n));
        }
        for (int j : pos[i]) {
            st.update(1, 0, n, j, n, - 2); 
        }
        for (int j : pos[i]) {
            l2.pb(st.get(1, 0, n, 0, j - 1)); 
            r2.pb(st.get(1, 0, n, j, n));
        }

        // debug(l1, r1, l2, r2); 

        int l = 1;
        int r = pos[i].size(); 
        while(l <= r) {
            int mid = (l + r) / 2; 
            bool ok = 0;

            for (int j = 0; j + mid - 1 < pos[i].size(); j++) {
                if (r1[j + mid - 1].mx - l1[j].mn >= 0 && r2[j + mid - 1].mn - l2[j].mx <= 0) {
                    ok = 1;
                    break; 
                }
            }   

            if (ok) {
                res = max(res, mid); 
                l = mid + 1;
            }
            else {
                r = mid - 1;
            }
        
        }
    }
    return res; 
}

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    int n; vector<int> a;
    cin >> n; 
    a.resize(n); 
    for (int i = 0; i < n; i++) {
        cin >> a[i]; 
    }    
    cout << sequence(n, a); 
}

Compilation message (stderr)

/usr/bin/ld: /tmp/ccePEMWq.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccWoAaPW.o:sequence.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status