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답안 #964489

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
964489 2024-04-17T01:49:35 Z Ghetto Spring cleaning (CEOI20_cleaning) C++17
53 / 100
 525 ms 262144 KB 
#include <bits/stdc++.h>
using namespace std;
using pii = pair<int, int>;
using pib = pair<int, bool>;
const int MAX_N = 1e5 + 5, MAX_Q = 1e5 + 5;;
 
int n, q;
vector<int> adj[MAX_N];
vector<int> upd[MAX_Q];
 
int root;
vector<int> child[MAX_N];
bool is_1[MAX_N];
void dfs1(int u, int par) {
    is_1[u] = (bool) (adj[u].size() == 1);
    for (int v : adj[u]) {
        if (v == par) continue;
        child[u].push_back(v);
        dfs1(v, u);
        if (is_1[v]) is_1[u] = !is_1[u];
    }
}
int n_1s[MAX_N], n_0s[MAX_N]; // From root to u
void dfs2(int u) {
    n_1s[u] += is_1[u], n_0s[u] += !is_1[u];
    for (int v : child[u]) {
        n_1s[v] += n_1s[u], n_0s[v] += n_0s[u];
        dfs2(v);
    }
}
int tot_n_1s, tot_n_0s;
void precomp1() {
    for (int i = 1; i <= n; i++) {
        if (adj[i].size() == 1) continue;
        root = i;
        dfs1(root, -1);
        break;
    }
    dfs2(root);
    for (int i = 1; i <= n; i++) 
        tot_n_1s += is_1[i], tot_n_0s += !is_1[i];     
}
 
int new_child_size[MAX_N];
int n_leaves[MAX_Q];
int extra_n_1s[MAX_Q];
unordered_set<int> queries_w_flip1[MAX_N];
void precomp2(int query) {
    for (int u : upd[query]) {
        extra_n_1s[query]++;
        if (new_child_size[u]) {
            n_leaves[query]++;
            if (queries_w_flip1[u].count(query)) queries_w_flip1[u].erase(query);
            else queries_w_flip1[u].insert(query);
        }
        new_child_size[u]++;
    }
    for (int u : upd[query]) new_child_size[u]--;
}
void init() {
    for (int i = 1; i <= n; i++) new_child_size[i] = child[i].size();
    int tot_n_leaves = 0;
    for (int i = 1; i <= n; i++) tot_n_leaves += (bool) child[i].empty();
    for (int i = 1; i <= q; i++) n_leaves[i] = tot_n_leaves;
}
 
unordered_map<int, int> queries_w_flip2[MAX_N]; // {query, prev flipped}
vector<pii> flip_path[MAX_Q]; // {high, low (not incl.)}
void dfs3(int u) {
    unordered_map<int, bool> spec_queries; // {query, flip state}
    for (int query : queries_w_flip1[u]) queries_w_flip2[u][query] = u;
 
    for (int v : child[u]) {
        dfs3(v);
 
        // if (queries_w_flip2[u].size() < queries_w_flip2[v].size()) queries_w_flip2[u].swap(queries_w_flip2[v]);
        for (pii el : queries_w_flip2[v]) {
            if (spec_queries.count(el.first)) {
                flip_path[el.first].push_back({el.second, u});
                spec_queries[el.first] = !spec_queries[el.first];
            } else {
                if (queries_w_flip2[u][el.first] == 0) queries_w_flip2[u][el.first] = el.second;
                else {
                    spec_queries[el.first] = false;
                    flip_path[el.first].push_back({el.second, u}); flip_path[el.first].push_back({queries_w_flip2[u][el.first], u});
                    queries_w_flip2[u].erase(el.first);
                }
            }
        }    
    }
 
    for (pib el : spec_queries) 
        if (el.second) queries_w_flip2[u][el.first] = u;
}
void precomp3() {
    dfs3(root);
    for (pii el : queries_w_flip2[root])
        flip_path[el.first].push_back({el.second, 0});
}
 
int main() {
    // freopen("spring.in", "r", stdin);
    // freopen("spring.out", "w", stdout);
 
    cin >> n >> q;
    for (int i = 1; i < n; i++) {
        int u, v; cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    for (int i = 1; i <= q; i++) {
        int s; cin >> s;
        for (int j = 1; j <= s; j++) {
            int u; cin >> u;
            upd[i].push_back(u);
        }
    }
 
    precomp1();
    init();
    for (int i = 1; i <= q; i++) precomp2(i);
    precomp3();
 
    for (int query = 1; query <= q; query++) {
        if (n_leaves[query] % 2 == 1) {
            cout << "-1" << '\n';
            continue;
        }
 
        int new_n_1s = tot_n_1s + extra_n_1s[query], new_n_0s = tot_n_0s;
        for (pii path : flip_path[query]) {
            int path_n_1s = n_1s[path.first] - n_1s[path.second], path_n_0s = n_0s[path.first] - n_0s[path.second];
            new_n_1s += path_n_0s - path_n_1s, new_n_0s += path_n_1s - path_n_0s;
        }
 
        int ans = new_n_1s + 2 * (new_n_0s - 1); assert(new_n_0s >= 1);
        cout << ans << '\n';
    }
}

Subtask #1
0.0 / 0.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 22616 KB Output is correct
2 Correct 86 ms 39252 KB Output is correct

Subtask #2
9.0 / 9.0

# 결과 실행 시간 메모리 Grader output
1 Correct 26 ms 24020 KB Output is correct
2 Correct 25 ms 24028 KB Output is correct
3 Correct 54 ms 27708 KB Output is correct
4 Correct 78 ms 32836 KB Output is correct
5 Correct 105 ms 33968 KB Output is correct

Subtask #3
9.0 / 9.0

# 결과 실행 시간 메모리 Grader output
1 Correct 28 ms 25740 KB Output is correct
2 Correct 28 ms 25772 KB Output is correct
3 Correct 99 ms 56148 KB Output is correct
4 Correct 166 ms 63384 KB Output is correct
5 Correct 90 ms 52240 KB Output is correct

Subtask #4
16.0 / 16.0

# 결과 실행 시간 메모리 Grader output
1 Correct 238 ms 97976 KB Output is correct
2 Correct 42 ms 29008 KB Output is correct
3 Correct 20 ms 24408 KB Output is correct
4 Correct 68 ms 53332 KB Output is correct
5 Correct 139 ms 75760 KB Output is correct
6 Correct 187 ms 96220 KB Output is correct

Subtask #5
19.0 / 19.0

# 결과 실행 시간 메모리 Grader output
1 Correct 186 ms 56588 KB Output is correct
2 Correct 145 ms 48252 KB Output is correct
3 Correct 101 ms 42132 KB Output is correct
4 Correct 147 ms 49316 KB Output is correct
5 Correct 171 ms 48668 KB Output is correct

Subtask #6
0 / 17.0

# 결과 실행 시간 메모리 Grader output
1 Correct 306 ms 91236 KB Output is correct
2 Runtime error 525 ms 262144 KB Execution killed with signal 9
3 Halted 0 ms 0 KB -

Subtask #7
0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 22616 KB Output is correct
2 Correct 86 ms 39252 KB Output is correct
3 Correct 26 ms 24020 KB Output is correct
4 Correct 25 ms 24028 KB Output is correct
5 Correct 54 ms 27708 KB Output is correct
6 Correct 78 ms 32836 KB Output is correct
7 Correct 105 ms 33968 KB Output is correct
8 Correct 28 ms 25740 KB Output is correct
9 Correct 28 ms 25772 KB Output is correct
10 Correct 99 ms 56148 KB Output is correct
11 Correct 166 ms 63384 KB Output is correct
12 Correct 90 ms 52240 KB Output is correct
13 Correct 238 ms 97976 KB Output is correct
14 Correct 42 ms 29008 KB Output is correct
15 Correct 20 ms 24408 KB Output is correct
16 Correct 68 ms 53332 KB Output is correct
17 Correct 139 ms 75760 KB Output is correct
18 Correct 187 ms 96220 KB Output is correct
19 Correct 186 ms 56588 KB Output is correct
20 Correct 145 ms 48252 KB Output is correct
21 Correct 101 ms 42132 KB Output is correct
22 Correct 147 ms 49316 KB Output is correct
23 Correct 171 ms 48668 KB Output is correct
24 Correct 306 ms 91236 KB Output is correct
25 Runtime error 525 ms 262144 KB Execution killed with signal 9
26 Halted 0 ms 0 KB -