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Submission #659599

# Submission time Handle Problem Language Result Execution time Memory
659599 2022-11-18T17:45:30 Z Lobo Star Trek (CEOI20_startrek) C++17
23 / 100
 1000 ms 51800 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++) {
            if(dpwc[j] || dpwupc[j]) SWb++;
            else SLb++; 
        }
    }


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

    dfs1(1,0);

    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

# Verdict Execution time Memory Grader output
1 Correct 17 ms 35540 KB Output is correct
2 Incorrect 55 ms 35720 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #2
0 / 7.0

# Verdict Execution time Memory Grader output
1 Incorrect 16 ms 35540 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 20 ms 35576 KB Output is correct
2 Correct 17 ms 35540 KB Output is correct
3 Correct 18 ms 35620 KB Output is correct
4 Correct 18 ms 35612 KB Output is correct
5 Correct 17 ms 35604 KB Output is correct
6 Correct 16 ms 35540 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 35576 KB Output is correct
2 Correct 17 ms 35540 KB Output is correct
3 Correct 18 ms 35620 KB Output is correct
4 Correct 18 ms 35612 KB Output is correct
5 Correct 17 ms 35604 KB Output is correct
6 Correct 16 ms 35540 KB Output is correct
7 Correct 61 ms 35756 KB Output is correct
8 Correct 60 ms 35796 KB Output is correct
9 Correct 48 ms 35720 KB Output is correct
10 Correct 58 ms 35724 KB Output is correct
11 Correct 57 ms 35724 KB Output is correct

Subtask #5
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 35576 KB Output is correct
2 Correct 17 ms 35540 KB Output is correct
3 Correct 18 ms 35620 KB Output is correct
4 Correct 18 ms 35612 KB Output is correct
5 Correct 17 ms 35604 KB Output is correct
6 Correct 16 ms 35540 KB Output is correct
7 Correct 61 ms 35756 KB Output is correct
8 Correct 60 ms 35796 KB Output is correct
9 Correct 48 ms 35720 KB Output is correct
10 Correct 58 ms 35724 KB Output is correct
11 Correct 57 ms 35724 KB Output is correct
12 Execution timed out 1072 ms 51800 KB Time limit exceeded
13 Halted 0 ms 0 KB -

Subtask #6
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 35576 KB Output is correct
2 Correct 17 ms 35540 KB Output is correct
3 Correct 18 ms 35620 KB Output is correct
4 Correct 18 ms 35612 KB Output is correct
5 Correct 17 ms 35604 KB Output is correct
6 Correct 16 ms 35540 KB Output is correct
7 Correct 61 ms 35756 KB Output is correct
8 Correct 60 ms 35796 KB Output is correct
9 Correct 48 ms 35720 KB Output is correct
10 Correct 58 ms 35724 KB Output is correct
11 Correct 57 ms 35724 KB Output is correct
12 Correct 16 ms 35540 KB Output is correct
13 Incorrect 56 ms 35724 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #7
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 35576 KB Output is correct
2 Correct 17 ms 35540 KB Output is correct
3 Correct 18 ms 35620 KB Output is correct
4 Correct 18 ms 35612 KB Output is correct
5 Correct 17 ms 35604 KB Output is correct
6 Correct 16 ms 35540 KB Output is correct
7 Correct 61 ms 35756 KB Output is correct
8 Correct 60 ms 35796 KB Output is correct
9 Correct 48 ms 35720 KB Output is correct
10 Correct 58 ms 35724 KB Output is correct
11 Correct 57 ms 35724 KB Output is correct
12 Execution timed out 1072 ms 51800 KB Time limit exceeded
13 Halted 0 ms 0 KB -

Subtask #8
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 35540 KB Output is correct
2 Incorrect 55 ms 35720 KB Output isn't correct
3 Halted 0 ms 0 KB -