oj.uz

Submission #659649

# Submission time Handle Problem Language Result Execution time Memory
659649 2022-11-18T21:13:31 Z Lobo Star Trek (CEOI20_startrek) C++17
78 / 100
 1000 ms 69504 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];
    }
}

int dw[maxn][2], dl[maxn][2], sdw[maxn][2], sdl[maxn][2], sbsz[maxn];
set<int> dl0s[maxn];

void calc(int u) {
    if(sdl[u][0] >= 1) {
        dw[u][0] = 1;
    }
    else {
        dw[u][0] = 0;
    }

    if(sdl[u][0] >= 2) {
        dw[u][1] = 1+sdw[u][1]+sdl[u][1];
    }
    else if(sdl[u][0] == 1) {
        dw[u][1] = 1+sdw[u][1]+sdl[u][1];
        int v1 = *dl0s[u].begin();
        dw[u][1]-= dw[v1][1];
    }
    else {
        dw[u][1] = 1+sdl[u][1];
    }
    dl[u][0] = 1-dw[u][0];
    dl[u][1] = sbsz[u]-dw[u][1];
}
void sol(int u, int ant) {
    dw[u][0] = 0;
    dl[u][0] = 0;
    sdw[u][0] = 0;
    sdl[u][0] = 0;
    dw[u][1] = 0;
    dl[u][1] = 0;
    sdw[u][1] = 0;
    sdl[u][1] = 0;
    sbsz[u] = 1;
    dl0s[u].clear();
    for(auto v : g[u]) if(v != ant) {
        sol(v,u);
        sdw[u][0]+= dw[v][0];
        sdw[u][1]+= dw[v][1];
        sdl[u][0]+= dl[v][0];
        sdl[u][1]+= dl[v][1];
        sbsz[u]+= sbsz[v];
        if(dl[v][0]) {
            dl0s[u].insert(v);
        }
    }

    calc(u);
}

void dfsrrt(int u, int ant) {
    SWb+= dw[u][1];
    for(auto v : g[u]) if(v != ant) {
        // take v off u
        sdw[u][0]-= dw[v][0];
        sdw[u][1]-= dw[v][1];
        sdl[u][0]-= dl[v][0];
        sdl[u][1]-= dl[v][1];
        sbsz[u]-= sbsz[v];
        if(dl[v][0]) {
            dl0s[u].erase(v);
        }
        calc(u);

        // put u into v
        sdw[v][0]+= dw[u][0];
        sdw[v][1]+= dw[u][1];
        sdl[v][0]+= dl[u][0];
        sdl[v][1]+= dl[u][1];
        sbsz[v]+= sbsz[u];
        if(dl[u][0]) {
            dl0s[v].insert(u);
        }
        calc(v);
        dfsrrt(v,u);

        // take u off v
        sdw[v][0]-= dw[u][0];
        sdw[v][1]-= dw[u][1];
        sdl[v][0]-= dl[u][0];
        sdl[v][1]-= dl[u][1];
        sbsz[v]-= sbsz[u];
        if(dl[u][0]) {
            dl0s[v].erase(u);
        }
        calc(v);

        // put v into u
        sdw[u][0]+= dw[v][0];
        sdw[u][1]+= dw[v][1];
        sdl[u][0]+= dl[v][0];
        sdl[u][1]+= dl[v][1];
        sbsz[u]+= sbsz[v];
        if(dl[v][0]) {
            dl0s[u].insert(v);
        }
        calc(u);
    }
}

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);
    }
}

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++;
    }

    sol(1,0);
    dfsrrt(1,0);
    SLb = n*n-SWb;

    // 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

# Verdict Execution time Memory Grader output
1 Correct 18 ms 35540 KB Output is correct
2 Correct 19 ms 35712 KB Output is correct

Subtask #2
0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 35540 KB Output is correct
2 Correct 18 ms 35540 KB Output is correct
3 Execution timed out 1091 ms 35540 KB Time limit exceeded
4 Halted 0 ms 0 KB -

Subtask #3
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 35544 KB Output is correct
2 Correct 17 ms 35616 KB Output is correct
3 Correct 19 ms 35624 KB Output is correct
4 Correct 18 ms 35616 KB Output is correct
5 Correct 22 ms 35584 KB Output is correct
6 Correct 18 ms 35636 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 35544 KB Output is correct
2 Correct 17 ms 35616 KB Output is correct
3 Correct 19 ms 35624 KB Output is correct
4 Correct 18 ms 35616 KB Output is correct
5 Correct 22 ms 35584 KB Output is correct
6 Correct 18 ms 35636 KB Output is correct
7 Correct 17 ms 35796 KB Output is correct
8 Correct 19 ms 35944 KB Output is correct
9 Correct 17 ms 35796 KB Output is correct
10 Correct 17 ms 35776 KB Output is correct
11 Correct 19 ms 35796 KB Output is correct

Subtask #5
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 35544 KB Output is correct
2 Correct 17 ms 35616 KB Output is correct
3 Correct 19 ms 35624 KB Output is correct
4 Correct 18 ms 35616 KB Output is correct
5 Correct 22 ms 35584 KB Output is correct
6 Correct 18 ms 35636 KB Output is correct
7 Correct 17 ms 35796 KB Output is correct
8 Correct 19 ms 35944 KB Output is correct
9 Correct 17 ms 35796 KB Output is correct
10 Correct 17 ms 35776 KB Output is correct
11 Correct 19 ms 35796 KB Output is correct
12 Correct 156 ms 60944 KB Output is correct
13 Correct 208 ms 68344 KB Output is correct
14 Correct 129 ms 54692 KB Output is correct
15 Correct 153 ms 54840 KB Output is correct
16 Correct 196 ms 54992 KB Output is correct

Subtask #6
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 35544 KB Output is correct
2 Correct 17 ms 35616 KB Output is correct
3 Correct 19 ms 35624 KB Output is correct
4 Correct 18 ms 35616 KB Output is correct
5 Correct 22 ms 35584 KB Output is correct
6 Correct 18 ms 35636 KB Output is correct
7 Correct 17 ms 35796 KB Output is correct
8 Correct 19 ms 35944 KB Output is correct
9 Correct 17 ms 35796 KB Output is correct
10 Correct 17 ms 35776 KB Output is correct
11 Correct 19 ms 35796 KB Output is correct
12 Correct 17 ms 35540 KB Output is correct
13 Correct 18 ms 35752 KB Output is correct
14 Correct 17 ms 35616 KB Output is correct
15 Correct 20 ms 35532 KB Output is correct
16 Correct 17 ms 35632 KB Output is correct
17 Correct 21 ms 35540 KB Output is correct
18 Correct 18 ms 35540 KB Output is correct
19 Correct 20 ms 35540 KB Output is correct
20 Correct 22 ms 35540 KB Output is correct
21 Correct 18 ms 35800 KB Output is correct
22 Correct 17 ms 35848 KB Output is correct
23 Correct 19 ms 35796 KB Output is correct
24 Correct 17 ms 35744 KB Output is correct
25 Correct 18 ms 35760 KB Output is correct
26 Correct 19 ms 35812 KB Output is correct
27 Correct 19 ms 35924 KB Output is correct
28 Correct 18 ms 35668 KB Output is correct
29 Correct 19 ms 35796 KB Output is correct
30 Correct 18 ms 35776 KB Output is correct

Subtask #7
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 35544 KB Output is correct
2 Correct 17 ms 35616 KB Output is correct
3 Correct 19 ms 35624 KB Output is correct
4 Correct 18 ms 35616 KB Output is correct
5 Correct 22 ms 35584 KB Output is correct
6 Correct 18 ms 35636 KB Output is correct
7 Correct 17 ms 35796 KB Output is correct
8 Correct 19 ms 35944 KB Output is correct
9 Correct 17 ms 35796 KB Output is correct
10 Correct 17 ms 35776 KB Output is correct
11 Correct 19 ms 35796 KB Output is correct
12 Correct 156 ms 60944 KB Output is correct
13 Correct 208 ms 68344 KB Output is correct
14 Correct 129 ms 54692 KB Output is correct
15 Correct 153 ms 54840 KB Output is correct
16 Correct 196 ms 54992 KB Output is correct
17 Correct 17 ms 35540 KB Output is correct
18 Correct 18 ms 35752 KB Output is correct
19 Correct 17 ms 35616 KB Output is correct
20 Correct 20 ms 35532 KB Output is correct
21 Correct 17 ms 35632 KB Output is correct
22 Correct 21 ms 35540 KB Output is correct
23 Correct 18 ms 35540 KB Output is correct
24 Correct 20 ms 35540 KB Output is correct
25 Correct 22 ms 35540 KB Output is correct
26 Correct 18 ms 35800 KB Output is correct
27 Correct 17 ms 35848 KB Output is correct
28 Correct 19 ms 35796 KB Output is correct
29 Correct 17 ms 35744 KB Output is correct
30 Correct 18 ms 35760 KB Output is correct
31 Correct 19 ms 35812 KB Output is correct
32 Correct 19 ms 35924 KB Output is correct
33 Correct 18 ms 35668 KB Output is correct
34 Correct 19 ms 35796 KB Output is correct
35 Correct 18 ms 35776 KB Output is correct
36 Correct 173 ms 62144 KB Output is correct
37 Correct 173 ms 69504 KB Output is correct
38 Correct 122 ms 55668 KB Output is correct
39 Correct 161 ms 56056 KB Output is correct
40 Correct 162 ms 56252 KB Output is correct
41 Correct 175 ms 66220 KB Output is correct
42 Correct 156 ms 66636 KB Output is correct
43 Correct 129 ms 53408 KB Output is correct
44 Correct 145 ms 56140 KB Output is correct
45 Correct 168 ms 55944 KB Output is correct

Subtask #8
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 35540 KB Output is correct
2 Correct 19 ms 35712 KB Output is correct
3 Correct 16 ms 35540 KB Output is correct
4 Correct 18 ms 35540 KB Output is correct
5 Execution timed out 1091 ms 35540 KB Time limit exceeded
6 Halted 0 ms 0 KB -