Submission #204699

#	Time	Username	Problem	Language	Result	Execution time	Memory
204699		waynetuinfor	Seats (IOI18_seats)	C++17	100 / 100	3813 ms	125668 KiB

seats

#pragma GCC optimize("O3")
#include "seats.h"

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

vector<vector<int>> gr;
vector<pair<int, int>> tree;
vector<int> tag;
vector<pair<int, int>> pos;
int n;

pair<int, int> Merge(const pair<int, int> &a, const pair<int, int> &b) {
    if (a.first < b.first) return a;
    if (a.first > b.first) return b;
    return make_pair(a.first, a.second + b.second);
}

void BuildTree(int l, int r, int o = 0) {
    if (r - l == 1) {
        tree[o] = make_pair(0, 1);
        if (l == n - 1) tree[o].first = n * 10;
        return;
    }
    int m = (l + r) >> 1;
    BuildTree(l, m, o * 2 + 1);
    BuildTree(m, r, o * 2 + 2);
    tree[o] = Merge(tree[o * 2 + 1], tree[o * 2 + 2]);
}

void Push(int o) {
    for (int v = 1; v <= 2; ++v) {
        tree[o * 2 + v].first += tag[o];
        tag[o * 2 + v] += tag[o];
    }
    tag[o] = 0;
}

void Modify(int l, int r, int ql, int qr, int v, int o = 0) {
    if (l >= qr || ql >= r) return;
    if (l >= ql && r <= qr) {
        tree[o].first += v;
        tag[o] += v;
        return;
    }
    Push(o);
    int m = (l + r) >> 1;
    Modify(l, m, ql, qr, v, o * 2 + 1);
    Modify(m, r, ql, qr, v, o * 2 + 2);
    tree[o] = Merge(tree[o * 2 + 1], tree[o * 2 + 2]);
}

void UpdateRect(int x, int y, int v) {
    array<int, 4> w = {gr[x - 1][y - 1], gr[x - 1][y], gr[x][y - 1], gr[x][y]};
    sort(w.begin(), w.end());
    Modify(0, n, w[0], w[1], v);
    Modify(0, n, w[2], w[3], v);
}

void give_initial_chart(int h, int w, vector<int> r, vector<int> c) {
    gr.resize(h + 2, vector<int>(w + 2, h * w));
    pos.resize(h * w);
    for (int i = 0; i < h * w; ++i) {
        gr[r[i] + 1][c[i] + 1] = i;
        pos[i] = make_pair(r[i] + 1, c[i] + 1);
    }
    n = h * w + 1;
    tree.resize(n * 4);
    tag.resize(n * 4);
    BuildTree(0, n);
    for (int i = 1; i <= h + 1; ++i) {
        for (int j = 1; j <= w + 1; ++j) UpdateRect(i, j, 1);
    }
}

int swap_seats(int a, int b) {
    for (int i = 0; i < 2; ++i) {
        for (int j = 0; j < 2; ++j) UpdateRect(pos[a].first + i, pos[a].second + j, -1);
    }
    for (int i = 0; i < 2; ++i) {
        for (int j = 0; j < 2; ++j) UpdateRect(pos[b].first + i, pos[b].second + j, -1);
    }
    assert(gr[pos[a].first][pos[a].second] == a);
    assert(gr[pos[b].first][pos[b].second] == b);
    swap(gr[pos[a].first][pos[a].second], gr[pos[b].first][pos[b].second]);
    swap(pos[a], pos[b]);
    for (int i = 0; i < 2; ++i) {
        for (int j = 0; j < 2; ++j) UpdateRect(pos[a].first + i, pos[a].second + j, 1);
    }
    for (int i = 0; i < 2; ++i) {
        for (int j = 0; j < 2; ++j) UpdateRect(pos[b].first + i, pos[b].second + j, 1);
    }
    assert(tree[0].first == 4);
    return tree[0].second;
}

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