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답안 #659645

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
659645 2022-11-18T21:04:50 Z Lobo Star Trek (CEOI20_startrek) C++17
43 / 100
 1000 ms 75248 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;
    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].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);
    }
}

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++) {
        sol(i,0);
        SWb+= dw[i][1];
        // cout << i << " " << dw[i][1] << endl;
    }
    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

# 결과 실행 시간 메모리 Grader output
1 Correct 22 ms 47356 KB Output is correct
2 Correct 43 ms 47508 KB Output is correct

Subtask #2
0 / 7.0

# 결과 실행 시간 메모리 Grader output
1 Correct 22 ms 47316 KB Output is correct
2 Correct 24 ms 47244 KB Output is correct
3 Execution timed out 1090 ms 47316 KB Time limit exceeded
4 Halted 0 ms 0 KB -

Subtask #3
8.0 / 8.0

# 결과 실행 시간 메모리 Grader output
1 Correct 22 ms 47316 KB Output is correct
2 Correct 24 ms 47316 KB Output is correct
3 Correct 23 ms 47372 KB Output is correct
4 Correct 23 ms 47272 KB Output is correct
5 Correct 25 ms 47308 KB Output is correct
6 Correct 23 ms 47264 KB Output is correct

Subtask #4
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 22 ms 47316 KB Output is correct
2 Correct 24 ms 47316 KB Output is correct
3 Correct 23 ms 47372 KB Output is correct
4 Correct 23 ms 47272 KB Output is correct
5 Correct 25 ms 47308 KB Output is correct
6 Correct 23 ms 47264 KB Output is correct
7 Correct 48 ms 47700 KB Output is correct
8 Correct 52 ms 47604 KB Output is correct
9 Correct 43 ms 47536 KB Output is correct
10 Correct 46 ms 47492 KB Output is correct
11 Correct 46 ms 47468 KB Output is correct

Subtask #5
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 22 ms 47316 KB Output is correct
2 Correct 24 ms 47316 KB Output is correct
3 Correct 23 ms 47372 KB Output is correct
4 Correct 23 ms 47272 KB Output is correct
5 Correct 25 ms 47308 KB Output is correct
6 Correct 23 ms 47264 KB Output is correct
7 Correct 48 ms 47700 KB Output is correct
8 Correct 52 ms 47604 KB Output is correct
9 Correct 43 ms 47536 KB Output is correct
10 Correct 46 ms 47492 KB Output is correct
11 Correct 46 ms 47468 KB Output is correct
12 Execution timed out 1083 ms 75248 KB Time limit exceeded
13 Halted 0 ms 0 KB -

Subtask #6
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 22 ms 47316 KB Output is correct
2 Correct 24 ms 47316 KB Output is correct
3 Correct 23 ms 47372 KB Output is correct
4 Correct 23 ms 47272 KB Output is correct
5 Correct 25 ms 47308 KB Output is correct
6 Correct 23 ms 47264 KB Output is correct
7 Correct 48 ms 47700 KB Output is correct
8 Correct 52 ms 47604 KB Output is correct
9 Correct 43 ms 47536 KB Output is correct
10 Correct 46 ms 47492 KB Output is correct
11 Correct 46 ms 47468 KB Output is correct
12 Correct 22 ms 47316 KB Output is correct
13 Correct 43 ms 47444 KB Output is correct
14 Correct 24 ms 47316 KB Output is correct
15 Correct 24 ms 47356 KB Output is correct
16 Correct 23 ms 47296 KB Output is correct
17 Correct 25 ms 47316 KB Output is correct
18 Correct 21 ms 47316 KB Output is correct
19 Correct 22 ms 47324 KB Output is correct
20 Correct 22 ms 47348 KB Output is correct
21 Correct 46 ms 47588 KB Output is correct
22 Correct 51 ms 47572 KB Output is correct
23 Correct 42 ms 47524 KB Output is correct
24 Correct 44 ms 47552 KB Output is correct
25 Correct 48 ms 47540 KB Output is correct
26 Correct 47 ms 47472 KB Output is correct
27 Correct 52 ms 47612 KB Output is correct
28 Correct 36 ms 47444 KB Output is correct
29 Correct 46 ms 47424 KB Output is correct
30 Correct 46 ms 47412 KB Output is correct

Subtask #7
0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 22 ms 47316 KB Output is correct
2 Correct 24 ms 47316 KB Output is correct
3 Correct 23 ms 47372 KB Output is correct
4 Correct 23 ms 47272 KB Output is correct
5 Correct 25 ms 47308 KB Output is correct
6 Correct 23 ms 47264 KB Output is correct
7 Correct 48 ms 47700 KB Output is correct
8 Correct 52 ms 47604 KB Output is correct
9 Correct 43 ms 47536 KB Output is correct
10 Correct 46 ms 47492 KB Output is correct
11 Correct 46 ms 47468 KB Output is correct
12 Execution timed out 1083 ms 75248 KB Time limit exceeded
13 Halted 0 ms 0 KB -

Subtask #8
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 22 ms 47356 KB Output is correct
2 Correct 43 ms 47508 KB Output is correct
3 Correct 22 ms 47316 KB Output is correct
4 Correct 24 ms 47244 KB Output is correct
5 Execution timed out 1090 ms 47316 KB Time limit exceeded
6 Halted 0 ms 0 KB -