Submission #447741

#	Time	Username	Problem	Language	Result	Execution time	Memory
447741		MilosMilutinovic	Seats (IOI18_seats)	C++14	37 / 100	4082 ms	56648 KiB

seats

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

#define pi pair<int, int>
#define X first
#define Y second

int h, w;
int r[1000005];
int c[1000005];

pair<int, int> pref_mx[1000005], pref_mn[1000005];
int small_change = 0;

struct ST{
    pair<pi, pi> st[8000005];
    pair<pi, pi> comb(pair<pi, pi> x, pair<pi, pi> y) {
        pair<pi, pi> ret;
        ret.X.X = max(x.X.X, y.X.X);
        ret.X.Y = max(x.X.Y, y.X.Y);
        ret.Y.X = min(x.Y.X, y.Y.X);
        ret.Y.Y = min(x.Y.Y, y.Y.Y);
        return ret;
    }
    void Build(int node, int ll, int rr) {
        if (ll == rr) {
            st[node] = {{r[ll], c[ll]}, {r[ll], c[ll]}};
            return;
        }
        int mid = ll + rr >> 1;
        Build(node * 2, ll, mid);
        Build(node * 2 + 1, mid + 1, rr);
        st[node] = comb(st[node * 2], st[node * 2 + 1]);
    }
    void Set(int node, int l, int r, int x, pi val) {
        if (l == r) {
            st[node].X = st[node].Y = val;
            return;
        }
        int mid = l + r >> 1;
        if (x <= mid) Set(node * 2, l, mid, x, val);
        else Set(node * 2 + 1, mid + 1, r, x, val);
        st[node] = comb(st[node * 2], st[node * 2 + 1]);
    }
    pair<pi, pi> Get(int node, int l, int r, int ql, int qr) {
        if (l > r || l > qr || r < ql) return {{0, 0}, {1e9, 1e9}};
        if (ql <= l && r <= qr) return st[node];
        int mid = l + r >> 1;
        return comb(Get(node * 2, l, mid, ql, qr), Get(node * 2 + 1, mid + 1, r, ql, qr));
    }
} ST;

void give_initial_chart(int H, int W, vector<int> R, vector<int> C) {
    h = H, w = W;
    for (int i = 0; i < h * w; i++) {
        r[i] = R[i];
        c[i] = C[i];
    }
    if (H + W <= 2000) ST.Build(1, 0, h * w - 1);
    else {
        pref_mx[0] = pref_mn[0] = {r[0], c[0]};
        for (int i = 1; i < h * w; i++) {
            pref_mx[i].first = max(pref_mx[i - 1].first, r[i]);
            pref_mx[i].second = max(pref_mx[i - 1].second, c[i]);
            pref_mn[i].first = min(pref_mn[i - 1].first, r[i]);
            pref_mn[i].second = min(pref_mn[i - 1].second, c[i]);
        }
        for (int i = 0; i < h * w; i++) {
            if ((pref_mx[i].first - pref_mn[i].first + 1) * (pref_mx[i].second - pref_mn[i].second + 1) == i + 1) {
                small_change++;
            }
        }
    }
}

int swap_seats(int a, int b) {
    if (h + w <= 2000) {
        swap(r[a], r[b]);
        swap(c[a], c[b]);
        ST.Set(1, 0, h * w - 1, a, {r[a], c[a]});
        ST.Set(1, 0, h * w - 1, b, {r[b], c[b]});
        int pos = 0, ans = 0;
        while (pos < h * w) {
            pair<pi, pi> rect = ST.Get(1, 0, h * w - 1, 0, pos);
            int P = (rect.X.X - rect.Y.X + 1) * (rect.X.Y - rect.Y.Y + 1);
            assert(P > pos);
            if (P == pos + 1) ans++, pos++;
            else pos = P - 1;
        }
        return ans;
    } else {
        if (h * w <= 10000) {
            swap(r[a], r[b]);
            swap(c[a], c[b]);
            int ans = 0;
            pair<int, int> mn, mx;
            mx = mn = {r[0], c[0]};
            for (int i = 0; i < h * w; i++) {
                mx.first = max(mx.first, r[i]);
                mx.second = max(mx.second, c[i]);
                mn.first = min(mn.first, r[i]);
                mn.second = min(mn.second, c[i]);
                if ((mx.first - mn.first + 1) * (mx.second - mn.second + 1) == i + 1) {
                  ans++;
                }
            }
            return ans;
        } else {
            if (a > b) swap(a, b);
            for (int i = a; i <= b; i++) {
                if ((pref_mx[i].first - pref_mn[i].first + 1) * (pref_mx[i].second - pref_mn[i].second + 1) == i + 1) {
                    small_change--;
                }
            }
            swap(r[a], r[b]);
            swap(c[a], c[b]);
            for (int i = a; i <= b; i++) {
                if (i == 0) pref_mx[i] = pref_mn[i] = {r[i], c[i]};
                else {
                    pref_mx[i].first = max(pref_mx[i - 1].first, r[i]);
                    pref_mx[i].second = max(pref_mx[i - 1].second, c[i]);
                    pref_mn[i].first = min(pref_mn[i - 1].first, r[i]);
                    pref_mn[i].second = min(pref_mn[i - 1].second, c[i]);
                }
            }
            for (int i = a; i <= b; i++) {
                if ((pref_mx[i].first - pref_mn[i].first + 1) * (pref_mx[i].second - pref_mn[i].second + 1) == i + 1) {
                    small_change++;
                }
            }
            return small_change;
        }
    }
}

Compilation message (stderr)

seats.cpp: In member function 'void ST::Build(int, int, int)':
seats.cpp:30:22: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   30 |         int mid = ll + rr >> 1;
      |                   ~~~^~~~
seats.cpp: In member function 'void ST::Set(int, int, int, int, std::pair<int, int>)':
seats.cpp:40:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   40 |         int mid = l + r >> 1;
      |                   ~~^~~
seats.cpp: In member function 'std::pair<std::pair<int, int>, std::pair<int, int> > ST::Get(int, int, int, int, int)':
seats.cpp:48:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   48 |         int mid = l + r >> 1;
      |                   ~~^~~

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