Submission #893463

#	Time	Username	Problem	Language	Result	Execution time	Memory
893463		vjudge1	Road Construction (JOI21_road_construction)	C++17	18 / 100	1220 ms	106656 KiB

road_construction

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define all(x) x.begin(), x.end()
#define size(x) (int)x.size()

template<class S, class T>
bool chmin(S &a, const T &b) {
    return a > b && (a = b) == b;
}
template<class S, class T>
bool chmax(S &a, const T &b) {
    return a < b && (a = b) == b;
}
const int inf = 1e9 + 7;
const int INF = 1e18 + 7;
const int mod = 998244353;

map<int, int> mp;

struct Segment_Tree {
    int n;
    vector<int> t, modify;
    Segment_Tree(int n) {
        this->n = n;
        t.assign(4 * n, INF);
        modify.assign(4 * n, 0);
    }
    
    void push(int v, int tl, int tr) {
        t[v] += modify[v];
        if (tl != tr) {
            modify[v << 1] += modify[v];
            modify[v << 1 | 1] += modify[v];
        }
        modify[v] = 0;
    }
    
    void upd(int v, int tl, int tr, int l, int r, int x) {
        if (modify[v]) push(v, tl, tr);
        if (tl > r || tr < l) return;
        if (tl >= l && tr <= r) {
            modify[v] += x;
            push(v, tl, tr);
            return;
        }
        int tm = (tl + tr) >> 1;
        upd(v << 1, tl, tm, l, r, x);
        upd(v << 1 | 1, tm + 1, tr, l, r, x);
        t[v] = min(t[v << 1], t[v << 1 | 1]);
    } void upd(int l, int r, int x) {
        upd(1, 1, n, l, r, x);
    }
    
    void upd_pos(int v, int tl, int tr, int i, int x) {
        if (modify[v]) push(v, tl, tr);
        if (tl == tr) {
            t[v] = x;
            return;
        }
        int tm = (tl + tr) >> 1;
        if (tm >= i) upd_pos(v << 1, tl, tm, i, x);
        else upd_pos(v << 1 | 1, tm + 1, tr, i, x);
        t[v] = min(t[v << 1], t[v << 1 | 1]);
    } void upd_pos(int i, int x) {
        upd_pos(1, 1, n, i, x);
    }
    
    int get(int v, int tl, int tr, int l, int r) {
        if (modify[v]) push(v, tl, tr);
        if (tl > r || tr < l) return INF;
        if (tl >= l && tr <= r) return t[v];
        int tm = (tl + tr) >> 1;
        return min(get(v << 1, tl, tm, l, r), get(v << 1 | 1, tm + 1, tr, l, r));
    } int get(int l, int r) {
        return get(1, 1, n, l, r);
    }
};

void compress(vector<int> &x, vector<int> &y, int n) {
    vector<int> v;
    for (int i = 0; i < n; ++i) {
        v.push_back(x[i]);
        v.push_back(y[i]);
    }
    sort(all(v));
    v.erase(unique(all(v)), v.end());
    for (int i = 0; i < size(v); ++i) {
        mp[v[i]] = i + 1;
    }
}

signed main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    int n, k;
    cin >> n >> k;
    vector<int> x(n), y(n);
    for (int i = 0; i < n; ++i) {
        cin >> x[i] >> y[i];
    }
    auto dist = [&](int i, int j) {
        return abs(x[i] - x[j]) + abs(y[i] - y[j]);
    };
    if (k == 1) {
        compress(x, y, n);
        Segment_Tree s(2 * n), b(2 * n);
        vector<pair<int, int>> v;
        for (int i = 0; i < n; ++i) {
            v.push_back({x[i], y[i]});
        }
        sort(all(v));
        for (int i = 0; i < n; ++i) {
            x[i] = v[i].first, y[i] = v[i].second;
        }
        int res = abs(x[0] - x[1]) + abs(y[0] - y[1]);
        for (int i = 0; i < n; ++i) {
            s.upd(1, mp[y[i]], y[i] + x[i]);
            b.upd(mp[y[i]], 2 * n, -y[i] + x[i]);
            chmin(res, min(s.get(1, mp[y[i]]), b.get(mp[y[i]], 2 * n)));
            s.upd(1, mp[y[i]], -y[i] - x[i]);
            b.upd(mp[y[i]], 2 * n, y[i] - x[i]);
            s.upd_pos(mp[y[i]], -y[i] - x[i]);
            b.upd_pos(mp[y[i]], y[i] - x[i]);
        }
        cout << res;
    } else if (n <= 1000) {
        int d[n][n];
        for (int i = 0; i < n; ++i) {
            for (int j = 0; j < n; ++j) {
                d[i][j] = dist(i, j);
            }
        }
        for (int k = 0; k < n; ++k) {
            for (int i = 0; i < n; ++i) {
                for (int j = 0; j < n; ++j) {
                    chmin(d[i][j], d[i][k] + d[k][j]);
                }
            }
        }
        multiset<int> st;
        for (int i = 0; i < n; ++i) {
            for (int j = i + 1; j < n; ++j) {
                st.insert(d[i][j]);
                if (size(st) > k) {
                    st.erase(--st.end());
                }
            }
        }
        for (int i : st) {
            cout << i << '\n';
        }
    } else {
        sort(all(x));
        multiset<pair<int, int>> st;
        for (int i = 0; i + 1 < n; ++i) {
            st.insert({dist(i, i + 1), i + 1});
        }
        vector<int> res;
        while (size(res) < k) {
            auto [d, i] = *st.begin();
            st.erase(st.begin());
            res.push_back(d);
            if (i + 1 < n) {
                st.insert({d + dist(i, i + 1), i + 1});
            }
        }
        for (int i : res) {
            cout << i << '\n';
        }
    }
}

• Subtask 1: 5 / 5
• Subtask 2: 6 / 6
• Subtask 3: 7 / 7
• Subtask 4: 0 / 20
• Subtask 5: 0 / 27
• Subtask 6: 0 / 35