제출 #384829

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
384829		kostia244	Designated Cities (JOI19_designated_cities)	C++17	39 / 100	657 ms	65276 KiB

designated_cities

#include<bits/stdc++.h>
using namespace std;
using ll = long long;
const int maxn = 2e5 + 12;
int n, cst[2*maxn];
ll edgesum = 0;
vector<array<int, 2>> g[maxn];


ll sub[maxn];
void sub_cost(int v, int p) {
    sub[v] = 0;
    for(auto [i, id] : g[v]) if(i != p) {
        sub_cost(i, v);
        sub[v] += sub[i] + cst[id];
    }
}
ll arb[maxn];
void reroot_cost(int v, int p, ll sum) {
    arb[v] = sum;
    for(auto [i, id] : g[v]) if(i!=p) {
        reroot_cost(i, v, sum-cst[id]+cst[id^1]);
    }
}
ll greedy[maxn], used[maxn];
array<ll, 2> find_leaf(int v, int p) {
    array<ll, 2> ans = {0, v};
    for(auto [i, id] : g[v]) if(i != p) {
        auto t = find_leaf(i, v);
        //cout << t[0]+( cst[id^1]*!used[id^1]) << endl;
        t[0] += cst[id^1]*!used[id^1];
        ans = max(ans, t);
    }
    return ans;
}

array<ll, 2> far[maxn];
void sub_far(int v, int p) {
    far[v] = {0, -(1ll<<56)};
    for(auto &[i, id] : g[v]) if(i != p) {
        sub_far(i, v);
        auto t = far[i];
        t[0] += cst[id^1];
        t[1] += cst[id^1];
        if(far[v][0] < t[0])
            swap(far[v][0], t[0]);
        far[v][1] = max(far[v][1], t[0]);
    }
}
ll F[maxn];
void reroot_far(int v, int p, ll over) {
    F[v] = max(far[v][0], over);
    //cout << v << " -- " << F[v] << endl;
    for(auto [i, id] : g[v]) if(i != p) {
        reroot_far(i, v, cst[id]+max(over, far[i][0]+cst[id^1] == far[v][0] ? far[v][1] : far[v][0]));
    }
}
ll solFor2 = 0;
int solve2() {
    sub_far(1, 0);
    reroot_far(1, 0, -(1ll<<60));
    array<ll, 2> sol = {-(1ll<<60), -1};
    for(int i = 1; i <= n; i++)
        sol = max(sol, {F[i]+arb[i], i});
    //cout << edgesum << " ? " << sol[0] << " " << sol[1] << endl;
    //cout << arb[3] << " " << arb[4] << endl;
    //cout << sol[0] << "/ " << edgesum << endl;
    solFor2 = edgesum - sol[0];
    return sol[1];
}

int par[maxn], par_edge[maxn], tin[maxn], tout[maxn], timer = 1;
int tinToV[maxn];
vector<ll> dep;
void find_pars(int v, int p, ll d) {
    tin[v] = timer++;
    dep[tin[v]] = d;
    tinToV[tin[v]] = v;
    for(auto [i, id] : g[v]) if(i != p) {
        par[i] = v;
        par_edge[i] = id^1;
        find_pars(i, v, d + cst[id^1]);
    }
    tout[v] = timer-1;
}

struct SegTree {
    struct Node {
        array<ll, 2> val;
        ll lazy;
        Node(int x = 0) : val{x, 0}, lazy(0) {}
        Node(array<ll, 2> x) : val{x[0], x[1]}, lazy(0) {}
        void apply(ll x) {
            lazy += x;
            val[0] += x;
        }
        void push(Node &l, Node &r) {
            l.apply(lazy), r.apply(lazy);
            lazy = 0;
        }
        friend Node operator+(const Node &a, const Node &b) {
            return Node(max(a.val, b.val));
        }
    };
    int n;
    vector<Node> tree;
    SegTree(int n) : n(n), tree(4*n) {}
    void build(int v, int l, int r, vector<ll> &dep) {
        if(l == r) {
            tree[v].val = {dep[l], l};
            return;
        }
        int mid = (l+r)/2;
        build(2*v, l, mid, dep);
        build(2*v+1, mid+1, r, dep);
        tree[v] = tree[2*v]+tree[2*v+1];
    }
    void build(vector<ll> &dep) {
        build(1, 1, n, dep);
    }
    void update(int v, int l, int r, int ql, int qr, ll add) {
        if(r < ql || qr < l) return;
        if(ql <= l && r <= qr) {
            tree[v].apply(add);
            return;
        }
        int mid = (l+r)/2;
        tree[v].push(tree[2*v], tree[2*v+1]);
        update(2*v, l, mid, ql, qr, add);
        update(2*v+1, mid+1, r, ql, qr, add);
        tree[v] = tree[2*v]+tree[2*v+1];
    }
    void update(int ql, int qr, ll add) {
        update(1, 1, n, ql, qr, add);
    }
    Node query(int v, int l, int r, int ql, int qr) {
        if(r < ql || qr < l) return Node();
        if(ql <= l && r <= qr) return tree[v];
        int mid = (l+r)/2;
        tree[v].push(tree[2*v], tree[2*v+1]);
        return query(2*v, l, mid, ql, qr) + query(2*v+1, mid+1, r, ql, qr);
    }
    array<ll, 2> query(int ql, int qr) {
        return query(1, 1, n, ql, qr).val;
    }
};

void solve(int v) {
    for(int i = 0; i < 2*n; i++) used[i] = 0;
    dep.resize(n+1);
    find_pars(v, 0, 0);
    sub_cost(v, 0);
    ll cur = sub[v];
    SegTree st(n);
    st.build(dep);
    //for(int i = 1; i <= n; i++)
    //    cout << st.query(tin[i], tin[i])[0] << " vs " << dep[i] << endl;
    //cout << '\n';
    for(int i = 2; i <= n; i++) {
        auto [add, x] = st.query(1, n);
        cur += add;
        x = tinToV[x];
        greedy[i] = edgesum - cur;
        for(; x != v && !used[par_edge[x]]; x = par[x]) {
            st.update(tin[x], tout[x], -cst[par_edge[x]]);
            used[par_edge[x]] = 1;
        }
    }
}

int main() {
    cin.tie(0)->sync_with_stdio(0);
    cin >> n;
    for(int f, t, x, y, i = 1; i < n; i++) {
        cin >> f >> t >> cst[2*i-1] >> cst[2*i-2];
        edgesum += cst[2*i-1];
        edgesum += cst[2*i-2];
        g[f].push_back({t, 2*i-2});
        g[t].push_back({f, 2*i-1});
    }
    sub_cost(1, 0);
    reroot_cost(1, 0, sub[1]);
    //for(int i = 1; i <= n; i++) cout << arb[i] << " "; cout << endl;
    auto point = solve2();

    memset(greedy, 0x4f, sizeof greedy);
    solve(point);

    int q;
    cin >> q;
    greedy[1] = edgesum-*max_element(arb+1, arb+n+1);
    //greedy[2] = solFor2;
    for(int t; q--;) {
        cin >> t;
        cout << greedy[t] << '\n';
    }
}

컴파일 시 표준 에러 (stderr) 메시지

designated_cities.cpp: In function 'int main()':
designated_cities.cpp:174:19: warning: unused variable 'x' [-Wunused-variable]
  174 |     for(int f, t, x, y, i = 1; i < n; i++) {
      |                   ^
designated_cities.cpp:174:22: warning: unused variable 'y' [-Wunused-variable]
  174 |     for(int f, t, x, y, i = 1; i < n; i++) {
      |                      ^

• Subtask 1: 6 / 6
• Subtask 2: 7 / 7
• Subtask 3: 9 / 9
• Subtask 4: 17 / 17
• Subtask 5: 0 / 17
• Subtask 6: 0 / 44