Submission #806796

#	Time	Username	Problem	Language	Result	Execution time	Memory
806796		thimote75	Wild Boar (JOI18_wild_boar)	C++14	12 / 100	124 ms	128884 KiB

wild_boar

#include <bits/stdc++.h>
#define int long long

using namespace std;

string to_string(string s) { return s; }
template <typename T> string to_string(T v) {
	bool first = true;
	string res = "[";
	for (const auto &x : v) {
		if (!first)
			res += ", ";
		first = false;
		res += to_string(x);
	}
	res += "]";
	return res;
}

template <typename A, typename B>
string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

void dbg_out() { cout << endl; }
template <typename Head, typename... Tail> void dbg_out(Head H, Tail... T) {
	cout << ' ' << to_string(H);
	dbg_out(T...);
}

#ifdef DEBUG
#define dbg(...) cout << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__)
#else
#define dbg(...)
#endif

struct State {
    int source = -1; int target = -1; int distance = 1e18;
    State next (int node, int next, int cost) {
        State st;
        st.source   = source == -1 ? next : source;
        st.distance = cost + distance;
        if (next == target) st.distance = 1e18;
        st.target   = node;

        return st;
    }
    bool operator< (const State &other) const {
        return distance < other.distance;
    }
};

const int MAXN = 2010;
struct CNT {
    signed dp[MAXN];
    signed lp[MAXN];
    signed vp[MAXN];
    int stage = 1;
    CNT () {
        for (int i = 0; i < MAXN; i ++)
            vp[i] = 0;
    }
    void clear () {
        stage ++;
    }
    void check (int node) {
        if (vp[node] != stage) {
            vp[node] = stage;
            lp[node] = dp[node];
        }
    } 
    int get (int x) {
        if (x == -1) return 0;
        check(x);
        return dp[x] - lp[x];
    }
    void insert (int x) {
        if (x == -1) return ;
        check(x);
        dp[x] ++;
    }
};

string to_string (State state) {
    if (state.distance == 1e18)
        return "State#";
    return "State[" + to_string(state.source + 1) + " => " + to_string(state.target + 1) + ", " + to_string(state.distance) + "]";
}

CNT map_buffer[5000]; int buffer_pos = 0;
CNT* get_buffer () {
    assert(buffer_pos < 5000);
    return map_buffer + (buffer_pos ++);
}

struct Matrix {
    vector<State> pcc;
    CNT* lst = get_buffer();
    CNT* fst = get_buffer();
    set<pair<int, int>> s;
    
    bool append (State state, bool apply = true) {
        if (pcc.size() >= 9) return false;
        if (lst->get(state.target) >= 3) return false;
        if (fst->get(state.source) >= 3) return false;
        if (s.find({ state.source, state.target }) != s.end()) return false;

        if (apply) {
            lst->insert(state.target);
            fst->insert(state.source);
            pcc.push_back(state);
            s.insert({ state.source, state.target });
        }
        return true;
    }

    vector<State> all () {
        return pcc;
    }
    int answer () {
        return pcc.size() == 0 ? -1 : pcc[0].distance;
    }
    void clear () {
        fst->clear();
        lst->clear();
        set<pair<int, int>>().swap(s);
    }

    Matrix merge (Matrix &other) {
        Matrix res;

        vector<State> all_states;
        for (State s1: all()) {
            for (State s2: other.all()) {
                State s3;
                if (s1.target == s2.source) continue ;

                s3.source   = s1.source;
                s3.target   = s2.target;
                s3.distance = s1.distance + s2.distance;

                all_states.push_back(s3);
            }
        }

        sort(all_states.begin(), all_states.end());
        for (State s : all_states)
            res.append(s);
        
        res.clear();
        buffer_pos = 0;
        return res;
    }
};
string to_string (Matrix matrix) {
    return "Mat" + to_string(matrix.all());
}
using vMatrix = vector<Matrix>;
using ti = pair<pair<int, int>, State>;
using pq = priority_queue<ti, vector<ti>, greater<ti>>;
template<typename T>
using grid  = vector<vector<T>>;
using idata = vector<int>;

using graph = grid<pair<int, int>>;

int N, M, T, L;
graph roads;

vMatrix dijkstra (int start) {
    pq q;

    vMatrix matrices(N);
    State startState;
    startState.distance = 0;
    q.push({ { 0, start }, startState });
    
    dbg(start);
    while (q.size() != 0) {
        const auto data = q.top(); q.pop();
        State state = data.second;
        int node = data.first.second;

        //if (state.distance >= 1e18) continue ;

        dbg(node, state.distance);

        if (!matrices[node].append( state )) continue ;
    
        for (const auto & road : roads[node]) {
            int next = road.first; int cost = road.second;

            State nextState = state.next(node, next, cost);
            if (!matrices[next].append(nextState, false)) continue ;

            q.push({ { nextState.distance, next }, nextState });
        }
    }

    for (Matrix &matrix : matrices)
        matrix.clear();

    buffer_pos = 0;
    return matrices;
}

struct SegTree {
    vector<Matrix> tree;

    int size, start, height;

    SegTree (int _s) {
        size   = _s;
        height = ceil(log2(size));
        start  = 1 << height;

        tree.resize(start << 1);
    }
    void modify (int node, Matrix mat) {
        node += start;
        tree[node] = mat;
        node >>= 1;

        while (node != 0) {
            tree[node] = tree[node * 2].merge(tree[node * 2 + 1]);
            node >>= 1;
        }
    }
    Matrix query (int right) {
        vector<int> queries;

        right += start;
        int limit = start;
        while (limit < right) {
            if ((right & 1) == 0) queries.push_back(right);

            right = (right - 1) >> 1;
            limit = limit >> 1;
        }

        if (limit == right) queries.push_back(right);

        reverse(queries.begin(), queries.end());

        Matrix mat = tree[queries[0]];
        for (int i = 1; i < queries.size(); i ++)
            mat = mat.merge( tree[queries[i]] );
        
        return mat;
    }
};

grid<Matrix> matrixGrid;

signed main () {
    ios_base::sync_with_stdio(false); cin.tie(NULL);

    cin >> N >> M >> T >> L;

    roads.resize(N);
    for (int i = 0; i < M; i ++) {
        int a, b, c;
        cin >> a >> b >> c;
        a --; b --;

        roads[a].push_back({ b, c });
        roads[b].push_back({ a, c });
    }

    for (int i = 0; i < N; i ++)
        matrixGrid.push_back( dijkstra(i) );
    
    idata DV(L);
    for (int i = 0; i < L; i ++) {
        cin >> DV[i];
        DV[i] --;
    }

    SegTree tree(L - 1);
    for (int i = 1; i < L; i ++)
        tree.modify(i - 1, matrixGrid[DV[i - 1]][DV[i]]);

    for (int i = 0; i < T; i ++) {
        int p, v;
        cin >> p >> v;
        p --;
        v --;

        DV[p] = v;
        if (p != 0) tree.modify(p - 1, matrixGrid[DV[p - 1]][DV[p]]);
        if (p != L - 1) tree.modify(p, matrixGrid[DV[p]][DV[p + 1]]);
        
        Matrix result = tree.query(L - 2);

        int answer = result.answer();
        if (answer == 1e18) answer = -1;
        cout << answer << "\n";
    }
}

Compilation message (stderr)

wild_boar.cpp: In member function 'Matrix SegTree::query(long long int)':
wild_boar.cpp:247:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  247 |         for (int i = 1; i < queries.size(); i ++)
      |                         ~~^~~~~~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 0 / 35
• Subtask 3: 0 / 15
• Subtask 4: 0 / 38