Submission #172989

#	Time	Username	Problem	Language	Result	Execution time	Memory
172989		keko37	Seats (IOI18_seats)	C++14	37 / 100	4027 ms	188504 KiB

seats

#include<bits/stdc++.h>

using namespace std;

typedef long long llint;
typedef pair <int, int> pi;

const int MAXN = 1000005;
const llint INF = 1000000000000000000LL;
const int BIG = 1000000000;

int n, m, ofs = 1;
vector <int> r, c;
vector < vector <int> > v;
llint a[MAXN], b[MAXN];
int dx[4] = {0, 0, 1, 1};
int dy[4] = {0, 1, 0, 1};

struct node {
    llint mn, prop;
    int br;
    node () {
        mn = 0; br = 1; prop = 0;
    }
    node (llint _mn, int _br) {
        mn = _mn; br = _br; prop = 0;
    }
} t[MAXN * 4];

node spoji (node a, node b) {
    if (a.mn < b.mn) return a;
    if (a.mn > b.mn) return b;
    return node(a.mn, a.br + b.br);
}

void tour_init () {
    while (ofs < n*m) ofs *= 2;
    for (int i = n*m; i < ofs; i++) {
        t[i + ofs] = node(INF, 1);
    }
    for (int i = ofs - 1; i > 0; i--) {
        t[i] = spoji(t[2 * i], t[2 * i + 1]);
    }
}

void propagate (int x) {
    if (t[x].prop == 0) return;
    if (x < ofs) {
        t[2*x].prop += t[x].prop;
        t[2*x+1].prop += t[x].prop;
    }
    t[x].mn += t[x].prop;
    t[x].prop = 0;
}

void update (int x, int from, int to, int lo, int hi, int val) {
    propagate(x);
    if (from <= lo && hi <= to) {
        t[x].prop += val;
        propagate(x);
        return;
    }
    if (to < lo || hi < from) return;
    update(2*x, from, to, lo, (lo + hi) / 2, val);
    update(2*x+1, from, to, (lo + hi) / 2 + 1, hi, val);
    t[x] = spoji(t[2*x], t[2*x+1]);
}

node upit (int x, int from, int to, int lo, int hi) {
    propagate(x);
    if (from <= lo && hi <= to) return t[x];
    if (to < lo || hi < from) return node(INF, 0);
    return spoji(upit(2*x, from, to, lo, (lo + hi) / 2), upit(2*x+1, from, to, (lo + hi) / 2 + 1, hi));
}

void two_by_two (int x, int y, int d) {
    int w[4] = {v[x][y], v[x][y + 1], v[x + 1][y], v[x + 1][y + 1]};
    sort(w, w + 4);
    if (w[0] < w[1]) update(1, w[0], w[1] - 1, 0, ofs - 1, d);
    if (w[2] < w[3]) update(1, w[2], w[3] - 1, 0, ofs - 1, BIG * d);
}

void give_initial_chart (int N, int M, vector <int> R, vector <int> C) {
    n = N; m = M; r = R; c = C;
    vector <int> e(m + 2, BIG);
    for (int i = 0; i < n + 2; i++) v.push_back(e);
    for (int i = 0; i < n * m; i++) {
        v[R[i] + 1][C[i] + 1] = i;
    }
    tour_init();
    for (int i = 0; i <= n; i++) {
        for (int j = 0; j <= m; j++) {
            two_by_two(i, j, 1);
        }
    }
}

int swap_seats (int a, int b) {
    vector <pi> u;
    for (int i = 0; i < 4; i++) u.push_back({r[a] + dx[i], c[a] + dy[i]});
    for (int i = 0; i < 4; i++) u.push_back({r[b] + dx[i], c[b] + dy[i]});
    sort(u.begin(), u.end());
    u.erase(unique(u.begin(), u.end()), u.end());

    for (auto p : u) two_by_two(p.first, p.second, -1);
    swap(v[r[a] + 1][c[a] + 1], v[r[b] + 1][c[b] + 1]);
    swap(r[a], r[b]);
    swap(c[a], c[b]);
    for (auto p : u) two_by_two(p.first, p.second, 1);

    node res = upit(1, 0, ofs - 1, 0, ofs - 1);
    if (res.mn > 4) return 0;
    return res.br;
}

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