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답안 #659611

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
659611 2022-11-18T18:08:24 Z Lobo Star Trek (CEOI20_startrek) C++17
43 / 100
 1000 ms 51812 KB 
#include<bits/stdc++.h>
using namespace std;
const long long inf = (long long) 1e18 + 10;
const int inf1 = (int) 1e9 + 10;
#define int long long
#define dbl long double
#define endl '\n'
#define sc second
#define fr first
#define mp make_pair
#define pb push_back
#define all(x) x.begin(), x.end()

const int maxn = 5e5+10;
const int mod = 1e9+7;

int n, d, dpw[maxn][2], dpl[maxn][2], dpwup[maxn][2], dplup[maxn][2];
vector<int> g[maxn];
int SL, SW, SL0, SW0, SWb, SLb;

void dfs1(int u, int ant) {
    dpw[u][1] = SW*dpw[u][0] + SL*(dpw[u][0]+dpl[u][0]); dpw[u][1]%= mod;
    dpl[u][1] = SW*dpl[u][0]; dpl[u][1]%= mod;

    int qtl = 0;
    for(auto v : g[u]) if(v != ant) {
        qtl+= dpl[v][0];
        dfs1(v,u);
    }

    for(auto v : g[u]) if(v != ant) {
        qtl-= dpl[v][0];
        if(qtl) {
            dpw[u][1]+= dpw[v][1]+dpl[v][1]; dpw[u][1]%= mod;
            dpl[u][1]+= 0;
        }
        else {
            dpw[u][1]+= dpl[v][1]; dpw[u][1]%= mod;
            dpl[u][1]+= dpw[v][1]; dpl[u][1]%= mod;
        }
        qtl+= dpl[v][0];
    }
}

map<int,int> wp[maxn];
int solwp(int u, int ant) {
    if(wp[u].count(ant)) return wp[u][ant];
    wp[u][ant] = 0;
    for(auto v : g[u]) if(v != ant) {
        if(solwp(v,u) == 0) wp[u][ant] = 1;
    }
    return wp[u][ant];
}

// void dfs0(int u, int ant) {
//     dpw[u][0] = 0;
//     for(auto v : g[u]) if(v != ant) {
//         dfs0(v,u);
//     }
//     for(auto v : g[u]) if(v != ant) {
//         if(solwp(v,u) == 0) dpw[u][0] = 1;
//     }
//     dpl[u][0] = 1-dpw[u][0];
// }

void dfs0(int u, int ant) {
    dpw[u][0] = 0;
    int qtl = 0;
    for(auto v : g[u]) if(v != ant) {
        dfs0(v,u);
        qtl+= dpl[v][0];
    }

    if(qtl) dpw[u][0] = 1;
    dpl[u][0] = 1-dpw[u][0];
}

void dfs0up(int u, int ant) {
    int qtl = 0;
    for(auto v : g[u]) if(v != ant) {
        qtl+= dpl[v][0];
    }

    for(auto v : g[u]) if(v != ant) {
        qtl-= dpl[v][0];
        if(qtl || dpwup[u][0]) {
            dpwup[v][0] = 0;
            dplup[v][0] = 1-dpwup[v][0];
        }
        else {
            dpwup[v][0] = 1;
            dplup[v][0] = 1-dpwup[v][0];
        }
        qtl+= dpl[v][0];
    }

    for(auto v : g[u]) if(v != ant) {
        dfs0up(v,u);
    }
}

int dpwc[maxn], dplc[maxn], dpwupc[maxn], dplupc[maxn];
void dfscnt(int u, int ant, int b) {
    dpwc[u] = 0;
    int qtl = 0;
    for(auto v : g[u]) if(v != ant) {
        dfscnt(v,u,b);
        qtl+= dplc[v];
    }

    if(qtl || u == b) dpwc[u] = 1;
    dplc[u] = 1-dpwc[u];
}

void dfscntup(int u, int ant, int b) {
    int qtl = 0;
    for(auto v : g[u]) if(v != ant) {
        qtl+= dplc[v];
    }

    for(auto v : g[u]) if(v != ant) {
        qtl-= dplc[v];
        if((qtl || dpwupc[u]) && v != b) {
            dpwupc[v] = 0;
            dplupc[v] = 1-dpwupc[v];
        }
        else {
            dpwupc[v] = 1;
            dplupc[v] = 1-dpwupc[v];
        }
        qtl+= dplc[v];
    }

    for(auto v : g[u]) if(v != ant) {
        dfscntup(v,u,b);
    }
}
void solve() {
    cin >> n >> d;

    for(int i = 1; i <= n-1; i++) {
        int u,v; cin >> u >> v;
        g[u].pb(v);
        g[v].pb(u);
    }

    dfs0(1,0);
    dpwup[1][0] = 0;
    dplup[1][0] = 1;
    dfs0up(1,0);
    for(int i = 1; i <= n; i++) {
        if(dpw[i][0] || dpwup[i][0]) SW0++;
        else SL0++;
    }

    for(int i = 1; i <= n; i++) {
        dfscnt(1,0,i);
        if(i == 1) {
            dpwupc[1] = 1;
            dplupc[1] = 0;
        }
        else {
            dpwupc[1] = 0;
            dplupc[1] = 1;
        }
        dfscntup(1,0,i);
        for(int j = 1; j <= n; j++) {
            // cout << i << " " << j << " " << (dpwc[j] || dpwupc[j]) << endl;
            if(dpwc[j] || dpwupc[j]) SWb++;
            else SLb++; 
        }
    }


    // cout << SWb << " " << SLb << endl;
    // cout << SW0 << " " << SL0 << endl;
    SWb%= mod;
    SLb%= mod;
    SW = SW0;
    SL = SL0;
    for(int i = 1; i <= d-1; i++) {
        int newSW = n*(SW*SW0%mod)%mod + SL*SWb; newSW%= mod;
        int newSL = n*(SW*SL0%mod)%mod + SL*SLb; newSL%= mod;
        SW = newSW;
        SL = newSL;
    }
    dfs1(1,0);
    // cout << SW << " " << SL << endl;
    cout << dpw[1][1] << endl;
}

int32_t main() {
    ios::sync_with_stdio(false); cin.tie(0);

    // freopen("in.in", "r", stdin);
    // freopen("out.out", "w", stdout);
    int tt = 1;
    // cin >> tt;
    while(tt--) {
        solve();
    }

}

Subtask #1
0.0 / 0.0

# 결과 실행 시간 메모리 Grader output
1 Correct 17 ms 35540 KB Output is correct
2 Correct 55 ms 35708 KB Output is correct

Subtask #2
0 / 7.0

# 결과 실행 시간 메모리 Grader output
1 Correct 16 ms 35540 KB Output is correct
2 Correct 17 ms 35540 KB Output is correct
3 Execution timed out 1086 ms 35580 KB Time limit exceeded
4 Halted 0 ms 0 KB -

Subtask #3
8.0 / 8.0

# 결과 실행 시간 메모리 Grader output
1 Correct 16 ms 35540 KB Output is correct
2 Correct 16 ms 35540 KB Output is correct
3 Correct 18 ms 35540 KB Output is correct
4 Correct 16 ms 35540 KB Output is correct
5 Correct 17 ms 35560 KB Output is correct
6 Correct 17 ms 35540 KB Output is correct

Subtask #4
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 16 ms 35540 KB Output is correct
2 Correct 16 ms 35540 KB Output is correct
3 Correct 18 ms 35540 KB Output is correct
4 Correct 16 ms 35540 KB Output is correct
5 Correct 17 ms 35560 KB Output is correct
6 Correct 17 ms 35540 KB Output is correct
7 Correct 53 ms 35760 KB Output is correct
8 Correct 57 ms 35796 KB Output is correct
9 Correct 41 ms 35724 KB Output is correct
10 Correct 57 ms 35652 KB Output is correct
11 Correct 57 ms 35668 KB Output is correct

Subtask #5
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 16 ms 35540 KB Output is correct
2 Correct 16 ms 35540 KB Output is correct
3 Correct 18 ms 35540 KB Output is correct
4 Correct 16 ms 35540 KB Output is correct
5 Correct 17 ms 35560 KB Output is correct
6 Correct 17 ms 35540 KB Output is correct
7 Correct 53 ms 35760 KB Output is correct
8 Correct 57 ms 35796 KB Output is correct
9 Correct 41 ms 35724 KB Output is correct
10 Correct 57 ms 35652 KB Output is correct
11 Correct 57 ms 35668 KB Output is correct
12 Execution timed out 1086 ms 51812 KB Time limit exceeded
13 Halted 0 ms 0 KB -

Subtask #6
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 16 ms 35540 KB Output is correct
2 Correct 16 ms 35540 KB Output is correct
3 Correct 18 ms 35540 KB Output is correct
4 Correct 16 ms 35540 KB Output is correct
5 Correct 17 ms 35560 KB Output is correct
6 Correct 17 ms 35540 KB Output is correct
7 Correct 53 ms 35760 KB Output is correct
8 Correct 57 ms 35796 KB Output is correct
9 Correct 41 ms 35724 KB Output is correct
10 Correct 57 ms 35652 KB Output is correct
11 Correct 57 ms 35668 KB Output is correct
12 Correct 16 ms 35540 KB Output is correct
13 Correct 55 ms 35724 KB Output is correct
14 Correct 17 ms 35492 KB Output is correct
15 Correct 18 ms 35532 KB Output is correct
16 Correct 17 ms 35540 KB Output is correct
17 Correct 18 ms 35556 KB Output is correct
18 Correct 17 ms 35560 KB Output is correct
19 Correct 19 ms 35572 KB Output is correct
20 Correct 17 ms 35540 KB Output is correct
21 Correct 59 ms 35772 KB Output is correct
22 Correct 59 ms 35796 KB Output is correct
23 Correct 41 ms 35668 KB Output is correct
24 Correct 55 ms 35720 KB Output is correct
25 Correct 55 ms 35708 KB Output is correct
26 Correct 57 ms 35764 KB Output is correct
27 Correct 62 ms 35800 KB Output is correct
28 Correct 34 ms 35668 KB Output is correct
29 Correct 57 ms 35728 KB Output is correct
30 Correct 58 ms 35724 KB Output is correct

Subtask #7
0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 16 ms 35540 KB Output is correct
2 Correct 16 ms 35540 KB Output is correct
3 Correct 18 ms 35540 KB Output is correct
4 Correct 16 ms 35540 KB Output is correct
5 Correct 17 ms 35560 KB Output is correct
6 Correct 17 ms 35540 KB Output is correct
7 Correct 53 ms 35760 KB Output is correct
8 Correct 57 ms 35796 KB Output is correct
9 Correct 41 ms 35724 KB Output is correct
10 Correct 57 ms 35652 KB Output is correct
11 Correct 57 ms 35668 KB Output is correct
12 Execution timed out 1086 ms 51812 KB Time limit exceeded
13 Halted 0 ms 0 KB -

Subtask #8
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 17 ms 35540 KB Output is correct
2 Correct 55 ms 35708 KB Output is correct
3 Correct 16 ms 35540 KB Output is correct
4 Correct 17 ms 35540 KB Output is correct
5 Execution timed out 1086 ms 35580 KB Time limit exceeded
6 Halted 0 ms 0 KB -