Submission #991047

#	Time	Username	Problem	Language	Result	Execution time	Memory
991047		Sharky	Seats (IOI18_seats)	C++17	0 / 100	197 ms	106056 KiB

seats

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

#define i32 int32_t

void give_initial_chart(i32 H, i32 W, vector<i32> R, vector<i32> C);
i32 swap_seats(i32 a, i32 b);

struct Node {
    int val, freq;
    Node operator + (Node& o) {
        if (val == o.val) return {val, freq + o.freq};
        if (val < o.val) return {val, freq};
        if (val > o.val) return {o.val, o.freq};
    }
};

const int inf = 1e9;

struct SegTree {
    int size = 1;
    vector<Node> seg;
    vector<int> lazy;
    void init(int n) {
        while (size < n) size *= 2;
        seg.resize(2 * size + 10);
        lazy.assign(2 * size + 10, 0);
    }
    void build(int l, int r, int id) {
        if (l == r) {
            seg[id] = {inf, 1};
            return;
        }
        int mid = (l + r) / 2;
        build(l, mid, id * 2);
        build(mid + 1, r, id * 2 + 1);
        seg[id] = seg[id * 2] + seg[id * 2 + 1];
    }
    void push(int id) {
        seg[id].val += lazy[id];
        if (id < size) {
            for (int i = 0; i < 2; i++) {
                lazy[id * 2 + i] += lazy[id];
            }
        }
        lazy[id] = 0;
    }
    void update(int ql, int qr, int tos, int l, int r, int id) {
        push(id);
        if (ql <= l && r <= qr) {
            lazy[id] += tos;
            push(id);
            return;
        }
        int mid = (l + r) / 2;
        update(ql, qr, tos, l, mid, id * 2);
        update(ql, qr, tos, mid + 1, r, id * 2 + 1);
        seg[id] = seg[id * 2] + seg[id * 2 + 1];
    }
    int query() {
        return seg[1].val == 4 ? seg[1].freq : 0;
    }
} st;

int n, h, w;
vector<int> rr, cc;
vector<vector<int>> g;

int I(int i, int j) {
    return i * w + j + 1;
}

void give_initial_chart(i32 H, i32 W, vector<i32> R, vector<i32> C) {
    h = H, w = W, n = h * w;
    st.init(n + 1);
    g = vector<vector<int>> (h + 2, vector<int> (w + 2, 0));
    rr.resize(n), cc.resize(n);
    for (int i = 0; i < n; i++) {
        g[R[i] + 1][C[i] + 1] = i;
        rr[i] = R[i] + 1, cc[i] = C[i] + 1;
    }
    for (int i = 0; i <= h; i++) {
        for (int j = 0; j <= w; j++) {
            vector<int> tmp;
            tmp.push_back(g[i][j]);
            tmp.push_back(g[i][j+1]);
            tmp.push_back(g[i+1][j]);
            tmp.push_back(g[i+1][j+1]);
            sort(tmp.begin(), tmp.end());
            st.update(tmp[0], tmp[1] - 1, 1, 1, n, 1);
            st.update(tmp[2], tmp[3] - 1, 1e9, 1, n, 1);
        }
    }
}

i32 swap_seats(i32 a, i32 b) {
    vector<pair<int, int>> e;
    for (int i = 0; i <= 1; i++) for (int j = 0; j <= 1; j++) {
        e.push_back({rr[a] - i, cc[a] - j});
        e.push_back({rr[b] - i, cc[b] - j});
    }
    sort(e.begin(), e.end());
    e.erase(unique(e.begin(), e.end()), e.end());
    for (auto& [i, j] : e) {
        vector<int> tmp;
        tmp.push_back(g[i][j]);
        tmp.push_back(g[i][j+1]);
        tmp.push_back(g[i+1][j]);
        tmp.push_back(g[i+1][j+1]);
        sort(tmp.begin(), tmp.end());
        st.update(tmp[0], tmp[1] - 1, 1, 1, n, 1);
        st.update(tmp[2], tmp[3] - 1, 1e9, 1, n, 1);
    }
    swap(rr[a], rr[b]);
    swap(cc[a], cc[b]);
    swap(g[rr[a]][cc[a]], g[rr[b]][cc[b]]);
    for (auto& [i, j] : e) {
        vector<int> tmp;
        tmp.push_back(g[i][j]);
        tmp.push_back(g[i][j+1]);
        tmp.push_back(g[i+1][j]);
        tmp.push_back(g[i+1][j+1]);
        sort(tmp.begin(), tmp.end());
        st.update(tmp[0], tmp[1] - 1, 1, 1, n, 1);
        st.update(tmp[2], tmp[3] - 1, 1e9, 1, n, 1);
    }
    i32 ans = st.query();
    return ans;
}

#ifndef EVAL

#include <cstdio>
#include <cstdlib>
#include <vector>

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() {
  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 member function 'Node Node::operator+(Node&)':
seats.cpp:16:5: warning: control reaches end of non-void function [-Wreturn-type]
   16 |     }
      |     ^

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