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Submission #585637

# Submission time Handle Problem Language Result Execution time Memory
585637 2022-06-29T06:57:59 Z 박상훈(#8384) Star Trek (CEOI20_startrek) C++17
78 / 100
 117 ms 22572 KB 
#include <bits/stdc++.h>

typedef long long ll;
using namespace std;
const int MOD = 1e9+7;
vector<int> adj[100100];
bool _win[100100], _win_pa[100100], _win_root[100100], ok[100100];
ll S[100100];

void dfs1(int s, int pa = -1){
    int wcnt = 0, lcnt = 0;
    for (auto &v:adj[s]) if (v!=pa){
        dfs1(v, s);
        if (_win[v]) wcnt++;
        else lcnt++;
    }

    if (!lcnt) _win[s] = 0;
    else _win[s] = 1;

    if (lcnt<=1) ok[s] = 1;
}

void dfs2(int s, int pa = -1){
    int wcnt = 0, lcnt = 0;
    for (auto &v:adj[s]) if (v!=pa){
        if (_win[v]) wcnt++;
        else lcnt++;
    }
    if (pa!=-1){
        if (_win_pa[s]) wcnt++;
        else lcnt++;
    }

    for (auto &v:adj[s]) if (v!=pa){
        if (_win[v]) wcnt--;
        else lcnt--;

        if (!lcnt) _win_pa[v] = 0;
        else _win_pa[v] = 1;

        if (_win[v]) wcnt++;
        else lcnt++;
    }

    if (!lcnt) _win_root[s] = 0;
    else _win_root[s] = 1;

    for (auto &v:adj[s]) if (v!=pa) dfs2(v, s);
}

int lscnt[100100], lscnt_pa[100100], lscnt_root[100100];
void dfs3(int s, int pa = -1){
    if (!_win[s]) lscnt[s]++;

    int lcnt = 0, wcnt = 0;
    for (auto &v:adj[s]) if (v!=pa){
        dfs3(v, s);
        if (!_win[v]) lcnt++;
        else wcnt++;
    }

    for (auto &v:adj[s]) if (v!=pa){
        if (lcnt==1 && !_win[v]) lscnt[s] += lscnt[v];
        else if (lcnt==0) lscnt[s] += lscnt[v];
    }
}

void dfs4(int s, int pa = -1){
    ///count
    int wcnt = 0, lcnt = 0, sum = 0;
    vector<int> L;
    for (auto &v:adj[s]) if (v!=pa){
        if (_win[v]) wcnt++;
        else lcnt++;
        sum += lscnt[v];

        if (!_win[v]) L.push_back(v);
    }
    if (pa!=-1){
        if (_win_pa[s]) wcnt++;
        else lcnt++;
        sum += lscnt_pa[s];
    }

    ///calc pa
    for (auto &v:adj[s]) if (v!=pa){
        if (_win[v]) wcnt--;
        else lcnt--;
        sum -= lscnt[v];

        if (!lcnt) lscnt_pa[v] = sum+1;
        else if (lcnt==1){
            if (pa!=-1 && !_win_pa[s]) lscnt_pa[v] = lscnt_pa[s];
            else{
                if (L[0]!=v) lscnt_pa[v] = lscnt[L[0]];
                else lscnt_pa[v] = lscnt[L[1]];
            }
        }

        if (_win[v]) wcnt++;
        else lcnt++;
        sum += lscnt[v];
    }

    ///calc root
    if (!lcnt) lscnt_root[s] = sum+1;
    else if (lcnt==1){
        if (pa!=-1 && !_win_pa[s]) lscnt_root[s] = lscnt_pa[s];
        else lscnt_root[s] = lscnt[L[0]];
    }

    for (auto &v:adj[s]) if (v!=pa) dfs4(v, s);
}

ll pw(ll a, ll e){
    if (!e) return 1;
    ll ret = pw(a, e/2);
    if (e&1) return ret*ret%MOD*a%MOD;
    return ret*ret%MOD;
}

int lscnt_naive[100100];
void naive(int n){
    for (int i=1;i<=n;i++){
        fill(_win, _win+n+1, 0);
        fill(lscnt, lscnt+n+1, 0);
        dfs1(i);
        dfs3(i);
        lscnt_naive[i] = lscnt[i];
        //lscnt_root[i] = lscnt_naive[i];
        assert(lscnt_root[i]==lscnt_naive[i]);
    }
    fill(_win, _win+n+1, 0);
    fill(lscnt, lscnt+n+1, 0);
    dfs1(1);
    dfs3(1);
}

int main(){
    int n;
    ll d;
    scanf("%d %lld", &n, &d);
    //if (n==2) {printf("%lld\n", pw(4, d)); return 0;}

    for (int i=1;i<=n-1;i++){
        int x, y;
        scanf("%d %d", &x, &y);
        adj[x].push_back(y);
        adj[y].push_back(x);
    }

    dfs1(1);
    dfs2(1);
    dfs3(1);
    dfs4(1);

    if (n<=1000) naive(n);

/*
    for (int i=1;i<=n;i++) printf("%d ", _win[i]); printf("\n");
    for (int i=1;i<=n;i++) printf("%d ", _win_pa[i]); printf("\n");
    for (int i=1;i<=n;i++) printf("%d ", _win_root[i]); printf("\n");
    for (int i=1;i<=n;i++) printf("%d ", lscnt[i]); printf("\n");
    for (int i=1;i<=n;i++) printf("%d ", lscnt_pa[i]); printf("\n");
    for (int i=1;i<=n;i++) printf("%d ", lscnt_root[i]); printf("\n");
*/

    ll ans = 0, T = 0, L = 0;
    for (int i=1;i<=n;i++){
        if (_win_root[i]) T += lscnt_root[i];
        else T -= lscnt_root[i], L++;

        if (T>=MOD) T -= MOD;
        if (T<0) T += MOD;
    }

    S[0] = L;
    for (int i=1;i<=d;i++){
        S[i] = (pw(n, i*2) * L % MOD + T * S[i-1] % MOD) % MOD;
    }

    if (_win[1]) ans = (pw(n, d*2) + MOD) - (lscnt_root[1] * S[d-1] % MOD);
    else ans = lscnt_root[1] * S[d-1] % MOD;
    ans %= MOD;

    printf("%lld\n", ans);

    return 0;
}

/*
int lcnt = 0;
    for (int i=1;i<=n;i++) if (!_win_root[i]) lcnt++;

    ll ans = 0;
    if (_win[1]) ans = (ll)n*n - (ll)lscnt[1] * lcnt;
    else ans = (ll)lscnt[1] * lcnt;
    ans %= MOD;

    printf("%lld\n", ans);
*/

Compilation message

startrek.cpp: In function 'int main()':
startrek.cpp:143:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  143 |     scanf("%d %lld", &n, &d);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~
startrek.cpp:148:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  148 |         scanf("%d %d", &x, &y);
      |         ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2644 KB Output is correct
2 Correct 33 ms 2736 KB Output is correct

Subtask #2
0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 3 ms 2772 KB Output is correct
3 Runtime error 77 ms 7616 KB Execution killed with signal 11
4 Halted 0 ms 0 KB -

Subtask #3
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 2 ms 2644 KB Output is correct
3 Correct 2 ms 2644 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 1 ms 2644 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 2 ms 2644 KB Output is correct
3 Correct 2 ms 2644 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 1 ms 2644 KB Output is correct
7 Correct 36 ms 2796 KB Output is correct
8 Correct 38 ms 2876 KB Output is correct
9 Correct 24 ms 2732 KB Output is correct
10 Correct 34 ms 2644 KB Output is correct
11 Correct 34 ms 2740 KB Output is correct

Subtask #5
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 2 ms 2644 KB Output is correct
3 Correct 2 ms 2644 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 1 ms 2644 KB Output is correct
7 Correct 36 ms 2796 KB Output is correct
8 Correct 38 ms 2876 KB Output is correct
9 Correct 24 ms 2732 KB Output is correct
10 Correct 34 ms 2644 KB Output is correct
11 Correct 34 ms 2740 KB Output is correct
12 Correct 116 ms 13708 KB Output is correct
13 Correct 97 ms 21412 KB Output is correct
14 Correct 49 ms 7608 KB Output is correct
15 Correct 60 ms 7292 KB Output is correct
16 Correct 62 ms 7392 KB Output is correct

Subtask #6
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 2 ms 2644 KB Output is correct
3 Correct 2 ms 2644 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 1 ms 2644 KB Output is correct
7 Correct 36 ms 2796 KB Output is correct
8 Correct 38 ms 2876 KB Output is correct
9 Correct 24 ms 2732 KB Output is correct
10 Correct 34 ms 2644 KB Output is correct
11 Correct 34 ms 2740 KB Output is correct
12 Correct 2 ms 2644 KB Output is correct
13 Correct 36 ms 2664 KB Output is correct
14 Correct 2 ms 2644 KB Output is correct
15 Correct 4 ms 2792 KB Output is correct
16 Correct 2 ms 2644 KB Output is correct
17 Correct 2 ms 2656 KB Output is correct
18 Correct 2 ms 2660 KB Output is correct
19 Correct 2 ms 2644 KB Output is correct
20 Correct 2 ms 2644 KB Output is correct
21 Correct 38 ms 2824 KB Output is correct
22 Correct 41 ms 2772 KB Output is correct
23 Correct 25 ms 2664 KB Output is correct
24 Correct 34 ms 2744 KB Output is correct
25 Correct 34 ms 2644 KB Output is correct
26 Correct 46 ms 3416 KB Output is correct
27 Correct 51 ms 3516 KB Output is correct
28 Correct 27 ms 3504 KB Output is correct
29 Correct 45 ms 3372 KB Output is correct
30 Correct 40 ms 3116 KB Output is correct

Subtask #7
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 2 ms 2644 KB Output is correct
3 Correct 2 ms 2644 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 1 ms 2644 KB Output is correct
7 Correct 36 ms 2796 KB Output is correct
8 Correct 38 ms 2876 KB Output is correct
9 Correct 24 ms 2732 KB Output is correct
10 Correct 34 ms 2644 KB Output is correct
11 Correct 34 ms 2740 KB Output is correct
12 Correct 116 ms 13708 KB Output is correct
13 Correct 97 ms 21412 KB Output is correct
14 Correct 49 ms 7608 KB Output is correct
15 Correct 60 ms 7292 KB Output is correct
16 Correct 62 ms 7392 KB Output is correct
17 Correct 2 ms 2644 KB Output is correct
18 Correct 36 ms 2664 KB Output is correct
19 Correct 2 ms 2644 KB Output is correct
20 Correct 4 ms 2792 KB Output is correct
21 Correct 2 ms 2644 KB Output is correct
22 Correct 2 ms 2656 KB Output is correct
23 Correct 2 ms 2660 KB Output is correct
24 Correct 2 ms 2644 KB Output is correct
25 Correct 2 ms 2644 KB Output is correct
26 Correct 38 ms 2824 KB Output is correct
27 Correct 41 ms 2772 KB Output is correct
28 Correct 25 ms 2664 KB Output is correct
29 Correct 34 ms 2744 KB Output is correct
30 Correct 34 ms 2644 KB Output is correct
31 Correct 46 ms 3416 KB Output is correct
32 Correct 51 ms 3516 KB Output is correct
33 Correct 27 ms 3504 KB Output is correct
34 Correct 45 ms 3372 KB Output is correct
35 Correct 40 ms 3116 KB Output is correct
36 Correct 92 ms 14976 KB Output is correct
37 Correct 117 ms 22572 KB Output is correct
38 Correct 46 ms 8424 KB Output is correct
39 Correct 64 ms 8644 KB Output is correct
40 Correct 78 ms 8532 KB Output is correct
41 Correct 90 ms 19532 KB Output is correct
42 Correct 113 ms 21384 KB Output is correct
43 Correct 49 ms 8392 KB Output is correct
44 Correct 80 ms 8720 KB Output is correct
45 Correct 74 ms 9244 KB Output is correct

Subtask #8
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2644 KB Output is correct
2 Correct 33 ms 2736 KB Output is correct
3 Correct 2 ms 2644 KB Output is correct
4 Correct 3 ms 2772 KB Output is correct
5 Runtime error 77 ms 7616 KB Execution killed with signal 11
6 Halted 0 ms 0 KB -