Submission #1291830

#	Time	Username	Problem	Language	Result	Execution time	Memory
1291830		anngela	Cats or Dogs (JOI18_catdog)	C++20	0 / 100	0 ms	400 KiB

catdog

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


struct Node {
    int sum, pmin;
    Node(int s = 0, int pm = 0) : sum(s), pmin(pm) {}
};

Node mergeNode(const Node &a, const Node &b) {
    Node c;
    c.sum = a.sum + b.sum;
    c.pmin = min(a.pmin, a.sum + b.pmin);
    return c;
}

struct SegTree {
    int n;
    vector<Node> st;

    void init(int n_){
        n = n_;
        st.assign(4*n + 5, Node());
    }

    void update(int p, int l, int r, int idx, int val) {
        if (l == r) {
            st[p] = Node(val, min(0, val));
            return;
        }
        int m = (l+r)/2;
        if (idx <= m) update(p*2, l, m, idx, val);
        else update(p*2+1, m+1, r, idx, val);
        st[p] = mergeNode(st[p*2], st[p*2+1]);
    }
};

static int Nglob;
static vector<vector<int>> G;  
static vector<int> val;        
static SegTree st;


int compute_danger() {
    Node root = st.st[1];
    if (root.pmin < 0) return 1;
    if (root.sum != 0) return 1;
    return 0;
}


void initialize(int N, std::vector<int> A, std::vector<int> B) {
    Nglob = N;

    G.assign(N, {});
    for (int i = 0; i < N - 1; i++) {
        int u = A[i];
        int v = B[i];
        G[u].push_back(v);
        G[v].push_back(u);
    }

    st.init(Nglob);
    val.assign(Nglob + 1, 0);
}

int cat(int X) {
    int pos = X + 1;
    val[pos] = +1;
    st.update(1, 1, Nglob, pos, +1);
    return compute_danger();
}



int dog(int X) {
    int pos = X + 1;
    val[pos] = -1;
    st.update(1, 1, Nglob, pos, -1);
    return compute_danger();
}

int neighbor(int X) {
    for (int v : G[X]) {
        int pos = v + 1;
        val[pos] = -val[pos];
        st.update(1, 1, Nglob, pos, val[pos]);
    }
    return compute_danger();
}

• Subtask 1: 0 / 8
• Subtask 2: 0 / 30
• Subtask 3: 0 / 62