Submission #729774

#	Time	Username	Problem	Language	Result	Execution time	Memory
729774		t6twotwo	Seats (IOI18_seats)	C++17	31 / 100	4046 ms	78084 KiB

seats

#include "seats.h"
#include <bits/stdc++.h>
using namespace std;
template <typename T>
struct segment_tree {
    int n;
    vector<T> s;
    T e;
    segment_tree() {
    }
    segment_tree(int _n) {
        n = 2 << __lg(_n);
        s.resize(2 * n - 1, T());
    }
    segment_tree(vector<T> &a) : segment_tree(a.size()) {
        for (int i = 0; i < a.size(); i++) {
            s[i + n - 1] = a[i];
        }
        for (int i = n - 2; i >= 0; i--) {
            s[i] = s[i * 2 + 1] + s[i * 2 + 2];
        }
    }
    void modify(int p, int l, int r, int x, const T &v) {
        if (l + 1 == r) {
            s[p] = v;
            return;
        }
        int m = (l + r + 1) / 2;
        if (x < m) {
            modify(p * 2 + 1, l, m, x, v);
        } else {
            modify(p * 2 + 2, m, r, x, v);
        }
        s[p] = s[p * 2 + 1] + s[p * 2 + 2];
    }
    void modify(int x, const T &v) {
        modify(0, 0, n, x, v);
    }
    T range_query(int p, int l, int r, int L, int R) {
        if (R <= l || r <= L) {
            return T();
        }
        if (L <= l && r <= R) {
            return s[p];
        }
        int m = (l + r + 1) / 2;
        return range_query(p * 2 + 1, l, m, L, R) + range_query(p * 2 + 2, m, r, L, R);
    }
    T range_query(int l, int r) {
        return range_query(0, 0, n, l, r);
    }
};
constexpr int inf = 1E9;
struct node {
    int l, r, u, d;
    node() : l(inf), r(-inf), u(inf), d(-inf) {
    }
    node(int L, int R, int U, int D) : l(L), r(R), u(U), d(D) {
    }
    int area() const {
        return (r - l + 1) * (d - u + 1);
    }
};
node operator+(const node &a, const node &b) {
    return node(min(a.l, b.l), max(a.r, b.r), min(a.u, b.u), max(a.d, b.d));
}
int N, M;
vector<int> A, B;
segment_tree<node> S;
void give_initial_chart(int H, int W, vector<int> R, vector<int> C) {
    N = H, M = W;
    A = R, B = C;
    vector<node> v(N * M);
    for (int i = 0; i < N * M; i++) {
        v[i] = node(B[i], B[i], A[i], A[i]);
    }
    S = segment_tree<node>(v);
}
int swap_seats(int u, int v) {
    swap(A[u], A[v]);
    swap(B[u], B[v]);
    if (N * M <= 10000) {
        int ans = 0;
        int L = M, R = -1;
        int U = N, D = -1;
        for (int i = 0; i < N * M; i++) {
            L = min(L, B[i]);
            R = max(R, B[i]);
            U = min(U, A[i]);
            D = max(D, A[i]);
            if ((R - L + 1) * (D - U + 1) == i + 1) {
                ans++;
            }
        }
        return ans;
    } else {
        S.modify(u, node(B[u], B[u], A[u], A[u]));
        S.modify(v, node(B[v], B[v], A[v], A[v]));
        int ans = 0;
        for (int i = 1; i <= N * M;) {
            int s = S.range_query(0, i).area();
            if (s == i) {
                ans++;
                i++;
            } else {
                i = s;
            }
        }
        return ans;
    }
}

Compilation message (stderr)

seats.cpp: In instantiation of 'segment_tree<T>::segment_tree(std::vector<_Tp>&) [with T = node]':
seats.cpp:77:29:   required from here
seats.cpp:16:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<node, std::allocator<node> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   16 |         for (int i = 0; i < a.size(); i++) {
      |                         ~~^~~~~~~~~~

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