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Submission #659640

# Submission time Handle Problem Language Result Execution time Memory
659640 2022-11-18T20:46:53 Z Lobo Star Trek (CEOI20_startrek) C++17
43 / 100
 1000 ms 63488 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];
// }

int dw[maxn][2], dl[maxn][2], sdw[maxn][2], sdl[maxn][2], sbsz[maxn];
vector<int> dl0s[maxn];
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;
    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].pb(v);
        }
    }

    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][0];
        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 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

# Verdict Execution time Memory Grader output
1 Correct 24 ms 47276 KB Output is correct
2 Correct 61 ms 47444 KB Output is correct

Subtask #2
0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 47232 KB Output is correct
2 Correct 28 ms 47324 KB Output is correct
3 Execution timed out 1085 ms 47272 KB Time limit exceeded
4 Halted 0 ms 0 KB -

Subtask #3
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 47316 KB Output is correct
2 Correct 22 ms 47268 KB Output is correct
3 Correct 22 ms 47236 KB Output is correct
4 Correct 23 ms 47296 KB Output is correct
5 Correct 22 ms 47356 KB Output is correct
6 Correct 28 ms 47308 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 47316 KB Output is correct
2 Correct 22 ms 47268 KB Output is correct
3 Correct 22 ms 47236 KB Output is correct
4 Correct 23 ms 47296 KB Output is correct
5 Correct 22 ms 47356 KB Output is correct
6 Correct 28 ms 47308 KB Output is correct
7 Correct 59 ms 47444 KB Output is correct
8 Correct 65 ms 47544 KB Output is correct
9 Correct 52 ms 47480 KB Output is correct
10 Correct 74 ms 47440 KB Output is correct
11 Correct 66 ms 47472 KB Output is correct

Subtask #5
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 47316 KB Output is correct
2 Correct 22 ms 47268 KB Output is correct
3 Correct 22 ms 47236 KB Output is correct
4 Correct 23 ms 47296 KB Output is correct
5 Correct 22 ms 47356 KB Output is correct
6 Correct 28 ms 47308 KB Output is correct
7 Correct 59 ms 47444 KB Output is correct
8 Correct 65 ms 47544 KB Output is correct
9 Correct 52 ms 47480 KB Output is correct
10 Correct 74 ms 47440 KB Output is correct
11 Correct 66 ms 47472 KB Output is correct
12 Execution timed out 1081 ms 63488 KB Time limit exceeded
13 Halted 0 ms 0 KB -

Subtask #6
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 47316 KB Output is correct
2 Correct 22 ms 47268 KB Output is correct
3 Correct 22 ms 47236 KB Output is correct
4 Correct 23 ms 47296 KB Output is correct
5 Correct 22 ms 47356 KB Output is correct
6 Correct 28 ms 47308 KB Output is correct
7 Correct 59 ms 47444 KB Output is correct
8 Correct 65 ms 47544 KB Output is correct
9 Correct 52 ms 47480 KB Output is correct
10 Correct 74 ms 47440 KB Output is correct
11 Correct 66 ms 47472 KB Output is correct
12 Correct 24 ms 47316 KB Output is correct
13 Correct 62 ms 47468 KB Output is correct
14 Correct 23 ms 47240 KB Output is correct
15 Correct 24 ms 47316 KB Output is correct
16 Correct 23 ms 47260 KB Output is correct
17 Correct 24 ms 47300 KB Output is correct
18 Correct 22 ms 47316 KB Output is correct
19 Correct 23 ms 47360 KB Output is correct
20 Correct 25 ms 47368 KB Output is correct
21 Correct 71 ms 47512 KB Output is correct
22 Correct 72 ms 47444 KB Output is correct
23 Correct 51 ms 47536 KB Output is correct
24 Correct 68 ms 47472 KB Output is correct
25 Correct 63 ms 47444 KB Output is correct
26 Correct 69 ms 47444 KB Output is correct
27 Correct 73 ms 47504 KB Output is correct
28 Correct 39 ms 47432 KB Output is correct
29 Correct 62 ms 47368 KB Output is correct
30 Correct 66 ms 47472 KB Output is correct

Subtask #7
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 47316 KB Output is correct
2 Correct 22 ms 47268 KB Output is correct
3 Correct 22 ms 47236 KB Output is correct
4 Correct 23 ms 47296 KB Output is correct
5 Correct 22 ms 47356 KB Output is correct
6 Correct 28 ms 47308 KB Output is correct
7 Correct 59 ms 47444 KB Output is correct
8 Correct 65 ms 47544 KB Output is correct
9 Correct 52 ms 47480 KB Output is correct
10 Correct 74 ms 47440 KB Output is correct
11 Correct 66 ms 47472 KB Output is correct
12 Execution timed out 1081 ms 63488 KB Time limit exceeded
13 Halted 0 ms 0 KB -

Subtask #8
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 24 ms 47276 KB Output is correct
2 Correct 61 ms 47444 KB Output is correct
3 Correct 21 ms 47232 KB Output is correct
4 Correct 28 ms 47324 KB Output is correct
5 Execution timed out 1085 ms 47272 KB Time limit exceeded
6 Halted 0 ms 0 KB -