Submission #677470

#	Time	Username	Problem	Language	Result	Execution time	Memory
677470		jhwest2	방벽 (JOI15_walls)	C++14	45 / 100	552 ms	29144 KiB

walls

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

typedef long long ll;
const int N = 202020;
const int INF = 1e9 + 10;

int n, m, a[N], b[N], ord[N], dir[N], pmin[N], pmax[N]; ll ans[N];
vector<int> q;
int main() {
    cin.tie(0); ios_base::sync_with_stdio(0);
    cin >> n >> m;
    for (int i = 1; i <= n; i++)
        cin >> a[i] >> b[i];
    for (int i = 1; i <= m; i++) {
        int x; cin >> x;
        if (!q.empty() && q.back() == x)
            continue;
        if (q.size() >= 2 && (q[q.size() - 2] < q.back()) == (q.back() < x))
            q.pop_back();
        q.push_back(x);
    }

    // determine direction 
    pmin[0] = pmax[0] = q[0];
    for (int i = 1; i < q.size(); i++) {
        pmin[i] = min(pmin[i - 1], q[i]);
        pmax[i] = max(pmax[i - 1], q[i]);
    }
    for (int i = 1; i <= n; i++) {
        int L = 0, R = (int)q.size();
        while (L < R) {
            int M = (L + R) / 2;
            if (pmin[M] < a[i] || pmax[M] > b[i])
                R = M;
            else
                L = M + 1;
        }
        if (R != q.size()) {
            if (pmin[L] < a[i])
                dir[i] = 1; // go left
            else
                dir[i] = 2; // go right
        }
    }
    for (int i = 1; i <= n; i++) {
        if (dir[i] == 1)
            a[i] += INF, b[i] += INF, ans[i] -= INF;
        if (dir[i] == 2)
            a[i] -= INF, b[i] -= INF, ans[i] -= INF;
    }

    for (int i = 1; i <= n; i++) 
        ord[i] = i;
    sort(ord + 1, ord + 1 + n, [&](auto i, auto j) {
        return b[i] - a[i] < b[j] - a[j];
    });

    set<pair<int, int>> st;
    set<pair<int, int>> pq;
    for (int i = 0; i < q.size(); i++) {
        st.insert({i, q[i]});
        if (i != 0)
            pq.insert({abs(q[i] - q[i - 1]), i - 1});
    }

    ll len = 0, cnt = (int)q.size() - 1;
    for (int i = 1; i < q.size(); i++)
        len += abs(q[i] - q[i - 1]);

    for (int i = 1; i <= n; i++) {
        if (dir[ord[i]] == 0)
            continue;

        int l = a[ord[i]], r = b[ord[i]];
        while (pq.size() >= 2 && pq.begin()->first <= r - l) {
            auto [x, y] = *pq.begin(); pq.erase(pq.begin());
            --cnt;

            auto it = st.lower_bound({y, q[y]});
            if (it == st.begin()) {
                st.erase(it);
                len -= x;
            }
            else if (next(next(it)) == st.end()) {
                st.erase(next(it));
                len -= x;
            }
            else {
                pq.erase({abs(it->second - prev(it)->second), prev(it)->first});
                it = st.erase(it);
                pq.erase({abs(it->second - next(it)->second), it->first});
                it = st.erase(it);
                pq.insert({abs(it->second - prev(it)->second), prev(it)->first});
                --cnt;
                len -= 2 * x;
            }
        } 
        int s = st.begin()->second;
        int t = next(st.begin())->second;

        if (cnt == 1) {
            if (s < t) {
                if (dir[ord[i]] == 1)
                    ans[ord[i]] += (ll)l - s + max(0, t - s - r + l);
                else
                    ans[ord[i]] += (ll)t - r;
            }
            else {
                if (dir[ord[i]] == 1)
                    ans[ord[i]] += (ll)l - t;
                else
                    ans[ord[i]] += (ll)s - r + max(0, s - t - r + l);
            }
        }
        else {
            ans[ord[i]] += len - cnt * (r - l);

            if (s < t) 
                ans[ord[i]] += abs(l - s);
            else 
                ans[ord[i]] += abs(r - s);
        }

        // cout << i << "!\n";
        // for (auto [x, y] : st)
        //     cout << y << ' ';
        // cout << '\n';
        // cout << len << ' ' << cnt << ' ' << "?\n";

        // cout << l << ' ' << r << ' ' << s << ' '<< t << "!!!\n";

    }
    for (int i = 1; i <= n; i++)
        cout << ans[i] << '\n';
}

Compilation message (stderr)

walls.cpp: In function 'int main()':
walls.cpp:26:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 |     for (int i = 1; i < q.size(); i++) {
      |                     ~~^~~~~~~~~~
walls.cpp:39:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |         if (R != q.size()) {
      |             ~~^~~~~~~~~~~
walls.cpp:61:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   61 |     for (int i = 0; i < q.size(); i++) {
      |                     ~~^~~~~~~~~~
walls.cpp:68:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   68 |     for (int i = 1; i < q.size(); i++)
      |                     ~~^~~~~~~~~~
walls.cpp:77:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   77 |             auto [x, y] = *pq.begin(); pq.erase(pq.begin());
      |                  ^

• Subtask 1: 0 / 10
• Subtask 2: 45 / 45
• Subtask 3: 0 / 45