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Submission #336898

# Submission time Handle Problem Language Result Execution time Memory
336898 2020-12-17T07:52:33 Z dolphingarlic Star Trek (CEOI20_startrek) C++14
38 / 100
 83 ms 16748 KB 
#include <bits/stdc++.h>
typedef long long ll;
using namespace std;

const ll MOD = 1e9 + 7;

vector<int> graph[100001];
ll win_as_root[100001], critical[100001];

void dfs1(int node = 1, int parent = 0) {
    for (int i : graph[node]) if (i != parent) {
        dfs1(i, node);
        win_as_root[node] += (win_as_root[i] == 0);
    }
    if (!win_as_root[node]) critical[node] = 1;
    for (int i : graph[node]) if (i != parent) {
        if ((win_as_root[node] == 1 && !win_as_root[i]) || !win_as_root[node])
            critical[node] += critical[i];
    }
}

void dfs2(int node = 1, int parent = 0, bool par_win = true, ll par_crit = 0) {
    win_as_root[node] += !par_win;

    ll all_crit = 0, lose_crit = 0;

    critical[node] = (win_as_root[node] == 0);
    all_crit += par_crit;
    if (!par_win) all_crit += par_crit;
    if ((win_as_root[node] == 1 && !par_win) || !win_as_root[node])
        critical[node] += par_crit;
    for (int i : graph[node]) if (i != parent) {
        all_crit += critical[i];
        if (!win_as_root[i]) lose_crit += critical[i];
        if ((win_as_root[node] == 1 && !win_as_root[i]) || !win_as_root[node])
            critical[node] += critical[i];
    }

    for (int i : graph[node]) if (i != parent) {
        if (win_as_root[node] - (win_as_root[i] == 0) == 0)
            dfs2(i, node, false, all_crit - critical[i] + 1);
        else if (win_as_root[node] - (win_as_root[i] == 0) == 1)
            dfs2(i, node, true, lose_crit - (win_as_root[i] ? critical[i] : 0));
        else
            dfs2(i, node, true, 0);
    }
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    ll n, d;
    cin >> n >> d;
    for (int i = 1; i < n; i++) {
        int u, v;
        cin >> u >> v;
        graph[u].push_back(v);
        graph[v].push_back(u);
    }
    dfs1();
    dfs2();

    ll lose_cnt = 0;
    for (int i = 1; i <= n; i++) lose_cnt += (win_as_root[i] == 0);
    if (win_as_root[1])
        cout << (n * n - lose_cnt * critical[1]) % MOD;
    else
        cout << lose_cnt * critical[1] % MOD;
    return 0;
}

Subtask #1
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2668 KB Output is correct
2 Incorrect 2 ms 2796 KB Output isn't correct

Subtask #2
0 / 7.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 2668 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2668 KB Output is correct
2 Correct 2 ms 2668 KB Output is correct
3 Correct 2 ms 2668 KB Output is correct
4 Correct 2 ms 2688 KB Output is correct
5 Correct 2 ms 2668 KB Output is correct
6 Correct 2 ms 2668 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2668 KB Output is correct
2 Correct 2 ms 2668 KB Output is correct
3 Correct 2 ms 2668 KB Output is correct
4 Correct 2 ms 2688 KB Output is correct
5 Correct 2 ms 2668 KB Output is correct
6 Correct 2 ms 2668 KB Output is correct
7 Correct 3 ms 2796 KB Output is correct
8 Correct 2 ms 2796 KB Output is correct
9 Correct 2 ms 2796 KB Output is correct
10 Correct 2 ms 2796 KB Output is correct
11 Correct 2 ms 2796 KB Output is correct

Subtask #5
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2668 KB Output is correct
2 Correct 2 ms 2668 KB Output is correct
3 Correct 2 ms 2668 KB Output is correct
4 Correct 2 ms 2688 KB Output is correct
5 Correct 2 ms 2668 KB Output is correct
6 Correct 2 ms 2668 KB Output is correct
7 Correct 3 ms 2796 KB Output is correct
8 Correct 2 ms 2796 KB Output is correct
9 Correct 2 ms 2796 KB Output is correct
10 Correct 2 ms 2796 KB Output is correct
11 Correct 2 ms 2796 KB Output is correct
12 Correct 77 ms 12524 KB Output is correct
13 Correct 83 ms 16748 KB Output is correct
14 Correct 58 ms 7528 KB Output is correct
15 Correct 80 ms 7404 KB Output is correct
16 Correct 72 ms 7532 KB Output is correct

Subtask #6
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2668 KB Output is correct
2 Correct 2 ms 2668 KB Output is correct
3 Correct 2 ms 2668 KB Output is correct
4 Correct 2 ms 2688 KB Output is correct
5 Correct 2 ms 2668 KB Output is correct
6 Correct 2 ms 2668 KB Output is correct
7 Correct 3 ms 2796 KB Output is correct
8 Correct 2 ms 2796 KB Output is correct
9 Correct 2 ms 2796 KB Output is correct
10 Correct 2 ms 2796 KB Output is correct
11 Correct 2 ms 2796 KB Output is correct
12 Correct 2 ms 2796 KB Output is correct
13 Incorrect 2 ms 2796 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #7
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2668 KB Output is correct
2 Correct 2 ms 2668 KB Output is correct
3 Correct 2 ms 2668 KB Output is correct
4 Correct 2 ms 2688 KB Output is correct
5 Correct 2 ms 2668 KB Output is correct
6 Correct 2 ms 2668 KB Output is correct
7 Correct 3 ms 2796 KB Output is correct
8 Correct 2 ms 2796 KB Output is correct
9 Correct 2 ms 2796 KB Output is correct
10 Correct 2 ms 2796 KB Output is correct
11 Correct 2 ms 2796 KB Output is correct
12 Correct 77 ms 12524 KB Output is correct
13 Correct 83 ms 16748 KB Output is correct
14 Correct 58 ms 7528 KB Output is correct
15 Correct 80 ms 7404 KB Output is correct
16 Correct 72 ms 7532 KB Output is correct
17 Correct 2 ms 2796 KB Output is correct
18 Incorrect 2 ms 2796 KB Output isn't correct
19 Halted 0 ms 0 KB -

Subtask #8
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2668 KB Output is correct
2 Incorrect 2 ms 2796 KB Output isn't correct