Submission #566589

#	Time	Username	Problem	Language	Result	Execution time	Memory
566589		elazarkoren	Seats (IOI18_seats)	C++17	0 / 100	4067 ms	84016 KiB

seats

#include <bits/stdc++.h>
#include "seats.h"
#define x first
#define y second
#define all(v) v.begin(), v.end()
#define chkmin(a, b) a = min(a, b)
#define chkmax(a, b) a = max(a, b)
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> pii;
typedef vector<pii> vii;

const int MAX_N = 1e6 + 5;

struct Seg {
    int n;
    vii seg;
    Seg () {}
    Seg (int m) {
        for (n = 1; n < m; n <<= 1);
        seg.resize(2 * n, {0, n});
    }
    void update(int i, int x) {
        seg[i += n] = {x, x};
        for (i >>= 1; i; i >>= 1) {
            seg[i].x = max(seg[i << 1].x, seg[i << 1 | 1].x);
            seg[i].y = min(seg[i << 1].y, seg[i << 1 | 1].y);
        }
    }
    pii query(int l, int r) {
        pii ans = {0, n};
        for (l += n, r += n; l < r; l >>= 1, r >>= 1) {
            if (l & 1) {
                chkmax(ans.x, seg[l].x);
                chkmin(ans.y, seg[l].y);
                l++;
            }
            if (r & 1) {
                --r;
                chkmax(ans.x, seg[r].x);
                chkmin(ans.y, seg[r].y);
            }
        }
        return ans;
    }
};


int r[MAX_N], c[MAX_N];
int n;

int ans = 0;
bitset<MAX_N> good;
int min_r[MAX_N], max_r[MAX_N], min_c[MAX_N], max_c[MAX_N];
Seg segr, segc;

set<int> interesting;

void give_initial_chart(int H, int W, std::vector<int> R, std::vector<int> C) {
    n = H * W;
    for (int i = 1; i <= H; i++) {
        for (int j = 1; j <= W; j++) {
            interesting.insert(i * j);
        }
    }
    interesting.insert(n);
    segr = Seg(n), segc = Seg(n);
    for (int i = 0; i < n; i++) {
        r[i] = R[i], c[i] = C[i];
        segr.update(i, r[i]);
        segc.update(i, c[i]);
    }
    min_r[0] = MAX_N, max_r[0] = 0;
    min_c[0] = MAX_N, max_c[0] = 0;
    for (int i = 0; i < n; i++) {
        if (i) {
            min_r[i] = min_r[i - 1], max_r[i] = max_r[i - 1];
            min_c[i] = min_c[i - 1], max_c[i] = max_c[i - 1];
        }
        chkmin(min_r[i], r[i]);
        chkmax(max_r[i], r[i]);
        chkmin(min_c[i], c[i]);
        chkmax(max_c[i], c[i]);
        good[i + 1] = (max_r[i] - min_r[i] + 1) * (max_c[i] - min_c[i] + 1) == i + 1;
        ans += good[i + 1];
    }
}

int swap_seats(int a, int b) {
    if (a > b) swap(a, b);
    swap(r[a], r[b]);
    swap(c[a], c[b]);
    segr.update(a, r[a]);
    segr.update(b, r[b]);
    segc.update(a, c[a]);
    segc.update(b, c[b]);
//    min_r[a] = MAX_N, max_r[a] = 0;
//    min_c[a] = MAX_N, max_c[a] = 0;
//    cout << a << " : " << "(" << r[a] << ", " << c[a] << ") - "
//         << b << " : (" << r[b] << ", " << c[b] << ") change:\n";
    for (auto it = interesting.lower_bound(a); *it < b; it++) {
        int i = *it;
        ans -= good[i];
//        if (i) {
//            min_r[i] = min_r[i - 1], max_r[i] = max_r[i - 1];
//            min_c[i] = min_c[i - 1], max_c[i] = max_c[i - 1];
//        }
//        chkmin(min_r[i], r[i]);
//        chkmax(max_r[i], r[i]);
//        chkmin(min_c[i], c[i]);
//        chkmax(max_c[i], c[i]);
//        bool last = good[i];
        auto [a, b] = segr.query(0, i);
        auto [c, d] = segc.query(0, i);
        good[i] = (a - b + 1) * (c - d + 1) == i;
//        good[i] = (max_r[i] - min_r[i] + 1) * (max_c[i] - min_c[i] + 1) == i + 1;
//        if (last != good[i]) {
//            cout << "\t" << i << " : (" << r[i] << ", " << c[i] << ")\n";
//        }
        ans += good[i];
    }
    return ans;
}
//2 3 2
//0 0
//1 0
//1 1
//0 1
//0 2
//1 2
//
//0 5
//0 5

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