Submission #569206

#	Time	Username	Problem	Language	Result	Execution time	Memory
569206		ngpin04	Seats (IOI18_seats)	C++17	11 / 100	4070 ms	161480 KiB

seats

#include "seats.h"
#include <bits/stdc++.h>
#define fi first
#define se second
#define mp make_pair
#define TASK ""
#define bit(x) (1LL << (x))
#define getbit(x, i) (((x) >> (i)) & 1)
#define ALL(x) (x).begin(), (x).end() 
using namespace std;
template <typename T1, typename T2> bool mini(T1 &a, T2 b) {
    if (a > b) {a = b; return true;} return false;
}
template <typename T1, typename T2> bool maxi(T1 &a, T2 b) {
    if (a < b) {a = b; return true;} return false;
}
mt19937_64 rd(chrono::steady_clock::now().time_since_epoch().count());

int rand(int l, int r) {
    return l + rd() % (r - l + 1);
}
const int N = 1e5 + 5; 
const int oo = 1e9;
const long long ooo = 1e18;
const int mod = 1e9 + 7; // 998244353;
const long double pi = acos(-1);

pair <int, int> add(pair <int, int> a, pair <int, int> b) {
    return {min(a.fi, b.fi), max(a.se, b.se)};
}

struct segtree {
    int n;
    vector <pair <int, int>> st;

    segtree(int _n = 0) {
        n = _n;
        st.assign(4 * n + 5, mp(0, 0));
    }

    void update(int id, int l, int r, int pos, int val) {
        if (l > pos || r < pos)
            return;
        if (l == r) {
            st[id] = {val, val};
            return;
        }
        int mid = (l + r) >> 1;
        update(id << 1, l, mid, pos, val);
        update(id << 1 | 1, mid + 1, r, pos, val);
        st[id].fi = min(st[id << 1].fi, st[id << 1 | 1].se);
        st[id].se = max(st[id << 1].se, st[id << 1 | 1].se);
    }

    void update(int pos, int val) {
        update(1, 0, n - 1, pos, val);
    }

    pair <int, int> getval(int id, int l, int r, int u, int v) {
        if (l > v || r < u)
            return mp(oo, -oo);
        if (l >= u && r <= v) 
            return st[id];
        int mid = (l + r) >> 1;
        auto [a, b] = getval(id << 1, l, mid, u, v);
        auto [x, y] = getval(id << 1 | 1, mid + 1, r, u, v);
        return {min(a, x), max(b, y)};
    }

    pair <int, int> getval(int l, int r) {
        return getval(1, 0, n - 1, l, r);
    }
};

segtree segX, segY;

int x[N];
int y[N];
int n,m;

void give_initial_chart(int H, int W, vector<int> R, vector<int> C) {
    n = H;
    m = W;
    segX = segY = segtree(n * m);
    for (int i = 0; i < n * m; i++) {
        x[i] = R[i], y[i] = C[i];
        segX.update(i, x[i]);
        segY.update(i, y[i]);
    }
}

int brute() {
    int ans = 0;
    int minx = oo, miny = oo, maxx = -oo, maxy = -oo;
    for (int i = 0; i < n * m; i++) {
        mini(minx, x[i]);
        maxi(maxx, x[i]);
        mini(miny, y[i]);
        maxi(maxy, y[i]);
        int dx = maxx - minx + 1;
        int dy = maxy - miny + 1;
        ans += (dx * dy == i + 1);
    }
    return ans;
}   

int sub2() {
    int res = 1;
    pair <int, int> rx = {x[0], x[0]}, ry{y[0], y[0]};

    int cur = 0;
    while (cur + 1 < n * m) {
        int dx = rx.se - rx.fi + 1;
        int dy = ry.se - ry.fi + 1;
        // cerr << cur << " " << dx << " " << dy << "\n";
        int cnt = dx * dy;
        if (cnt == cur + 1) {
            int d = min(dx, dy);
            rx = add(rx, segX.getval(0, cur + d));
            ry = add(ry, segY.getval(0, cur + d));
            cur += d;
            res++;
        } else {
            rx = add(rx, segX.getval(0, cnt - 1));
            ry = add(ry, segY.getval(0, cnt - 1));
            cur = cnt - 1;
        }
    }
    return res;
}

int swap_seats(int a, int b) {
    swap(x[a], x[b]);
    segX.update(a, x[a]);
    segX.update(b, x[b]);
    swap(y[a], y[b]);
    segY.update(a, y[a]);
    segY.update(b, y[b]);
    if (n * m <= 10000)
        return brute();
    if (max(n, m) <= 1000)
        return sub2();
    return -1;
}

//#include "grader.cpp"

• Subtask 1: 5 / 5
• Subtask 2: 6 / 6
• Subtask 3: 0 / 20
• Subtask 4: 0 / 6
• Subtask 5: 0 / 33
• Subtask 6: 0 / 30