Submission #894083

#	Time	Username	Problem	Language	Result	Execution time	Memory
894083		box	Cats or Dogs (JOI18_catdog)	C++17	0 / 100	1 ms	2904 KiB

catdog

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

#define ar array
#define sz(v) int(std::size(v))
using i64 = long long;

const int MAXN = 1e5;
const int INF = 1e9;

int N;
vector<int> adj[MAXN];
int must[MAXN];

ar<int, 2> dfs(int p, int i) {
    ar<int, 2> c{0, 0};
    for (int j : adj[i]) if (p != j) {
        auto v = dfs(i, j);
        c[0] += min(v[0], v[1] + 1);
        c[1] += min(v[0] + 1, v[1]);
    }
    if (must[i] & 1) c[0] = INF;
    if (must[i] & 2) c[1] = INF;
    return c;
}

int brute_dp() {
    auto v = dfs(-1, 0);
    return min(v[0], v[1]);
}

void initialize(int N, vector<int> A, vector<int> B) {
    for (int h = 0; h < N - 1; h++) {
        auto [i, j] = make_pair(A[h], B[h]);
        adj[i].push_back(j);
        adj[j].push_back(i);
    }
}

int cat(int i) {
    must[i] |= 1;
    return brute_dp();
}

int dog(int i) {
    must[i] |= 2;
    return brute_dp();
}

int neighbor(int i) {
    must[i] = 0;
    return brute_dp();
}

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