Submission #767069

#	Time	Username	Problem	Language	Result	Execution time	Memory
767069		marvinthang	Seats (IOI18_seats)	C++17	100 / 100	867 ms	141972 KiB

seats

/*************************************
*    author: marvinthang             *
*    created: 26.06.2023 11:25:22    *
*************************************/

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

using namespace std;

#define                  fi  first
#define                  se  second
#define                left  ___left
#define               right  ___right
#define                TIME  (1.0 * clock() / CLOCKS_PER_SEC)
#define             MASK(i)  (1LL << (i))
#define           BIT(x, i)  ((x) >> (i) & 1)
#define  __builtin_popcount  __builtin_popcountll
#define              ALL(v)  (v).begin(), (v).end()
#define           REP(i, n)  for (int i = 0, _n = (n); i < _n; ++i)
#define          REPD(i, n)  for (int i = (n); i--; )
#define        FOR(i, a, b)  for (int i = (a), _b = (b); i < _b; ++i) 
#define       FORD(i, b, a)  for (int i = (b), _a = (a); --i >= _a; ) 
#define       FORE(i, a, b)  for (int i = (a), _b = (b); i <= _b; ++i) 
#define      FORDE(i, b, a)  for (int i = (b), _a = (a); i >= _a; --i) 
#define        scan_op(...)  istream & operator >> (istream &in, __VA_ARGS__ &u)
#define       print_op(...)  ostream & operator << (ostream &out, const __VA_ARGS__ &u)
#ifdef LOCAL
    #include "debug.h"
#else
    #define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
    #define DB(...) 23
    #define db(...) 23
    #define debug(...) 23
#endif

template <class U, class V> scan_op(pair <U, V>)  { return in >> u.first >> u.second; }
template <class T> scan_op(vector <T>)  { for (size_t i = 0; i < u.size(); ++i) in >> u[i]; return in; }
template <class U, class V> print_op(pair <U, V>)  { return out << '(' << u.first << ", " << u.second << ')'; }
template <size_t i, class T> ostream & print_tuple_utils(ostream &out, const T &tup) { if constexpr(i == tuple_size<T>::value) return out << ")";  else return print_tuple_utils<i + 1, T>(out << (i ? ", " : "(") << get<i>(tup), tup); }
template <class ...U> print_op(tuple<U...>) { return print_tuple_utils<0, tuple<U...>>(out, u); }
template <class Con, class = decltype(begin(declval<Con>()))> typename enable_if <!is_same<Con, string>::value, ostream&>::type operator << (ostream &out, const Con &con) { out << '{'; for (__typeof(con.begin()) it = con.begin(); it != con.end(); ++it) out << (it == con.begin() ? "" : ", ") << *it; return out << '}'; }
template <class A, class B> bool minimize(A &a, B b)  { if (a > b) { a = b; return true; } return false; }
template <class A, class B> bool maximize(A &a, B b)  { if (a < b) { a = b; return true; } return false; }

struct Node {
    int lazy, cnt_min, mi;
    Node(int cm = 0, int m = 0): lazy(0), cnt_min(cm), mi(m) {}
    void add(int v) {
        lazy += v;
        mi += v;
    }
    Node operator + (const Node &other) const {
        if (mi == other.mi) return Node(cnt_min + other.cnt_min, mi);
        return mi < other.mi ? Node(cnt_min, mi) : Node(other.cnt_min, other.mi);
    }
};

// end of template

int H, W, cnt;
vector <vector <int>> board;
vector <int> R, C;
vector <Node> st;

bool inside(int x, int y) {
    return 0 <= x && x < H && 0 <= y && y < W;
}

int delta(int i) {
    if (!i) return 0;
    int res = 0;
    REP(sx, 2) REP(sy, 2) {
        int cnt = 0;
        REP(tx, 2) REP(ty, 2) {
            int u = R[i] - sx + tx;
            int v = C[i] - sy + ty;
            cnt += !inside(u, v) || board[u][v] > i;
        }
        res += cnt == 1 || cnt == 3 ? 1 : -1;
    }
    return res;
}

void build(int i, int l, int r, vector <int> &pref) {
    if (r - l == 1) {
        st[i] = Node(1, pref[l]);
        return;
    }
    int m = l + r >> 1;
    build(i << 1, l, m, pref);
    build(i << 1 | 1, m, r, pref);
    st[i] = st[i << 1] + st[i << 1 | 1];
}

void pushDown(int i) {
    if (!st[i].lazy) return;
    st[i << 1].add(st[i].lazy);
    st[i << 1 | 1].add(st[i].lazy);
    st[i].lazy = 0;
}

void update(int i, int l, int r, int u, int v, int val) {
    if (l >= v || r <= u) return;
    if (u <= l && r <= v) {
        st[i].add(val);
        return;
    }
    pushDown(i);
    int m = l + r >> 1;
    update(i << 1, l, m, u, v, val);
    update(i << 1 | 1, m, r, u, v, val);
    st[i] = st[i << 1] + st[i << 1 | 1];
}

void give_initial_chart(int h, int w, vector <int> r, vector <int> c) {
    H = h; W = w; R = r; C = c;
    board.resize(H, vector<int>(W));
    REP(i, H * W) board[R[i]][C[i]] = i;
    st.resize(H * W * 4 + 23);
    vector <int> pref(H * W);
    FOR(i, 1, H * W) pref[i] = pref[i - 1] + delta(i);
    build(1, 0, H * W, pref);
}

int swap_seats(int a, int b) {
    set <pair <int, int>> ss;
    for (int x = -1; x <= 1; ++x) for (int y = -1; y <= 1; ++y) {
        int u = R[a] + x, v = C[a] + y;
        if (inside(u, v)) ss.insert(make_pair(board[u][v], delta(board[u][v])));
        u = R[b] + x, v = C[b] + y;
        if (inside(u, v)) ss.insert(make_pair(board[u][v], delta(board[u][v])));
    }
    swap(board[R[a]][C[a]], board[R[b]][C[b]]);
    swap(R[a], R[b]);
    swap(C[a], C[b]);
    for (auto [x, r]: ss) update(1, 0, H * W, x, H * W, delta(x) - r);
    return st[1].cnt_min;
}

#ifdef LOCAL
#include <cstdio>
#include <cstdlib>
#include <vector>
#include "seats.h"

namespace {

int read_int() {
  int x;
  if (scanf("%d", &x) != 1) {
    fprintf(stderr, "Error while reading input\n");
    exit(1);
  }
  return x;
}

}  // namespace

int main() {
    file("seats");
  int H = read_int();
  int W = read_int();
  int Q = read_int();
  std::vector<int> R(H * W), C(H * W);
  for (int i = 0; i < H * W; ++i) {
    R[i] = read_int();
    C[i] = read_int();
  }
  std::vector<int> A(Q), B(Q);
  for (int j = 0; j < Q; ++j) {
    A[j] = read_int();
    B[j] = read_int();
  }

  give_initial_chart(H, W, R, C);
  for (int j = 0; j < Q; ++j) {
    int answer = swap_seats(A[j], B[j]);
    printf("%d\n", answer);
  }
  return 0;
}
#endif

Compilation message (stderr)

seats.cpp: In function 'void build(int, int, int, std::vector<int>&)':
seats.cpp:90:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   90 |     int m = l + r >> 1;
      |             ~~^~~
seats.cpp: In function 'void update(int, int, int, int, int, int)':
seats.cpp:110:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  110 |     int m = 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