Submission #565851

#	Time	Username	Problem	Language	Result	Execution time	Memory
565851		MilosMilutinovic	Seats (IOI18_seats)	C++14	100 / 100	3822 ms	128260 KiB

seats

#include "seats.h"
#include <bits/stdc++.h>

using namespace std;

const int MAX = 1000005;

long long st[4 * MAX][2], lzy[4 * MAX];

void build(int node, int l, int r) {
  st[node][0] = 0;
  st[node][1] = r - l + 1;
  lzy[node] = 0;
  if (l == r) {
    return;
  }
  int mid = l + r >> 1;
  build(node + node, l, mid);
  build(node + node + 1, mid + 1, r);
}

void pull(int node, int l, int r) {
  st[node][0] = min(st[node + node][0], st[node + node + 1][0]);
  st[node][1] = 0;
  if (st[node][0] == st[node + node][0]) {
    st[node][1] += st[node + node][1];
  }
  if (st[node][0] == st[node + node + 1][0]) {
    st[node][1] += st[node + node + 1][1];
  }
}

void push(int node, int l, int r) {
  if (l == r) {
    return;
  }
  st[node + node][0] += lzy[node];
  st[node + node + 1][0] += lzy[node];
  lzy[node + node] += lzy[node];
  lzy[node + node + 1] += lzy[node];
  lzy[node] = 0;
}

void modify(int node, int l, int r, int ll, int rr, int v) {
  if (l > rr || r < ll) return;
  if (ll <= l && r <= rr) {
    st[node][0] += v;
    lzy[node] += v;
    push(node, l, r);
    return;
  }
  int mid = l + r >> 1;
  push(node, l, r);
  modify(node + node, l, mid, ll, rr, v);
  modify(node + node + 1, mid + 1, r, ll, rr, v);
  pull(node, l, r);
}

vector<vector<int>> a;
int h, w;
int x[MAX];
int y[MAX];

vector<int> dx = {1, 0, 1};
vector<int> dy = {0, 1, 1};

void add(int p, int i, int j, int v) {
  vector<int> vals(1, p);
  for (int d = 0; d < 3; d++) {
    int ni = i + dx[d];
    int nj = j + dy[d];
    if (ni >= 0 && ni < h && nj >= 0 && nj < w) {
      vals.push_back(a[ni][nj]);
    } else {
      vals.push_back(h * w);
    }
  }
  sort(vals.begin(), vals.end());
  if (vals[0] < vals[1]) {
    modify(1, 0, h * w - 1, vals[0], vals[1] - 1, v);
  }
  if (vals[2] < vals[3]) {
    modify(1, 0, h * w - 1, vals[2], vals[3] - 1, v * MAX);
  }
}

void give_initial_chart(int H, int W, vector<int> R, vector<int> C) {
  h = H;
  w = W;
  a.resize(H);
  for (int i = 0; i < H; i++) {
    a[i].resize(W);
  }
  for (int i = 0; i < H * W; i++) {
    x[i] = R[i];
    y[i] = C[i];
    a[x[i]][y[i]] = i;
  }
  build(1, 0, h * w - 1);
  for (int i = 0; i < H * W; i++) {
    add(i, x[i], y[i], 1);
  }
  for (int i = 0; i < H; i++) {
    add(h * w, i, -1, 1);
  }
  for (int j = -1; j < W; j++) {
    add(h * w, -1, j, 1);
  }
}

vector<int> di = {0, 0, -1, -1};
vector<int> dj = {0, -1, 0, -1};

bool Valid(int i, int j) {
  return i >= 0 && i < h && j >= 0 && j < w;
}

vector<pair<int, int>> aux;

int swap_seats(int i, int j) {
  for (int d = 0; d < 4; d++) {
    {
      int ni = x[i] + di[d];
      int nj = y[i] + dj[d];
      aux.emplace_back(ni, nj);
    }
    {
      int ni = x[j] + di[d];
      int nj = y[j] + dj[d];
      aux.emplace_back(ni, nj);
    }
  }
  sort(aux.begin(), aux.end());
  aux.erase(unique(aux.begin(), aux.end()), aux.end());
  for (auto& c : aux) {
    if (Valid(c.first, c.second)) {
      add(a[c.first][c.second], c.first, c.second, -1);
    } else {
      add(h * w, c.first, c.second, -1);
    }
  }
  swap(a[x[i]][y[i]], a[x[j]][y[j]]);
  swap(x[i], x[j]);
  swap(y[i], y[j]);
  for (auto& c : aux) {
    if (Valid(c.first, c.second)) {
      add(a[c.first][c.second], c.first, c.second, 1);
    } else {
      add(h * w, c.first, c.second, 1);
    }
  }
  aux.clear();
  return st[1][1];
}

Compilation message (stderr)

seats.cpp: In function 'void build(int, int, int)':
seats.cpp:17:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   17 |   int mid = l + r >> 1;
      |             ~~^~~
seats.cpp: In function 'void modify(int, int, int, int, int, int)':
seats.cpp:52:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   52 |   int mid = l + r >> 1;
      |             ~~^~~

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