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답안 #600104

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
600104 2022-07-20T13:05:19 Z jasmin Star Trek (CEOI20_startrek) C++14
23 / 100
 1000 ms 13672 KB 
#include<bits/stdc++.h>
using namespace std;
#define int long long

const int mod=1e9+7;
struct matrix{
    int a=1;
    int b=0;
    int c=0;
    int d=1;
};
matrix zero={1, 0, 0, 1};
vector<int> mul(matrix a, vector<int> b){
    vector<int> ans(2, -1);
    ans[0]=(a.a*b[0])%mod +(a.b*b[1])%mod;
    ans[0]%=mod;
    ans[1]=(a.c*b[0])%mod +(a.d*b[1])%mod;
    ans[1]%=mod;
    return ans;
}
matrix multiply(matrix a, matrix b){
    matrix ans;
    ans.a=(a.a*b.a)%mod + (a.b*b.c)%mod;
    ans.a%=mod;
    ans.b=(a.a*b.b)%mod + (a.b*b.d)%mod;
    ans.b%=mod;
    ans.c=(a.c*b.a)%mod + (a.d*b.c)%mod;
    ans.c%=mod;
    ans.d=(a.c*b.b)%mod + (a.d+b.d)%mod;
    ans.d%=mod;
    return ans;
}
matrix power(matrix a, int e){
    if(e==0){
        return zero;
    }

    matrix res=power(a, e/2);
    res=multiply(res, res);
    if(e%2==1){
        res=multiply(res, a);
    }
    return res;
}

vector<int> win_down;
vector<int> redchild;
bool dfs_win(int v, int p, vector<vector<int> >& adi){
    for(auto u: adi[v]){
        if(u==p) continue;

        if(!dfs_win(u, v, adi)){
            redchild[v]=u;
            win_down[v]++;
        }
    }
    return win_down[v]>0;
}
vector<bool> win_up;
int violet=0; //=n-c
void dfs_win2(int v, int p, vector<vector<int> >& adi){
    if(p==-1){
        win_up[v]=false;
    }
    else if(win_down[v]){
        if(win_down[p]==0 && !win_up[p]){
            win_up[v]=true;
        }
        else{
            win_up[v]=false;
        }
    }
    else if(win_down[v]==0){
        if(win_down[p]==1 && !win_up[p]){
            win_up[v]=true;
        }
        else{
            win_up[v]=false;
        }
    }
    if(!win_up[v] && !win_down[v]){
        violet++;
    } 

    for(auto u: adi[v]){
        if(u!=p) dfs_win2(u, v, adi);
    }
}

int redforce=0;
void dfs(int v, int p, vector<vector<int> >& adi){

    if(win_down[v]==0){
        redforce++;
        for(auto u: adi[v]){
            if(u!=p) dfs(u, v, adi);
        }
    }
    else if(win_down[v]==1){
        dfs(redchild[v], v, adi);
    }
}

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int n, d;
    cin >> n >> d;
    vector<vector<int> > adi(n);
    for(int i=0; i<n-1; i++){
        int a,b;
        cin >> a >> b;
        adi[a-1].push_back(b-1);
        adi[b-1].push_back(a-1);
    }

    int G=0; int R=0;
    int g1=-1; int r1=-1;
    for(int i=n-1; i>=0; i--){
        violet=0;
        redforce=0;
        win_up.assign(n, 0);
        redchild.assign(n, -1);
        win_down.assign(n, 0);

        bool we_win=dfs_win(i, -1, adi);
        dfs_win2(i, -1, adi);
        dfs(i, -1, adi);

        if(we_win){
            g1=n;
            r1=n-redforce;
        }
        else{
            g1=0;
            r1=redforce;
        }
        //cout << g1 << " " << r1 << " " << redforce << " " << violet << "\n";
        G+=g1;
        R+=r1;
    }

    /*cout << g1 << " " << r1 << "\n";
    cout << G << " " << R << " " << "\n" << n*n-G << " " << n*n-R << "\n";
    cout << n-violet << " " << violet << "\n";*/

    matrix m1={g1, r1, -1, -1};
    //matrix m2={G, R, n*n-G, n*n-R};
    matrix m2={G, n*n-G, R, n*n-R};
    matrix p=power(m2, d-1);
    //cout << p.a << " " << p.b << "\n" << p.c << " " << p.d << "\n";
    vector<int> ans=mul(m1, mul(p, {n-violet, violet}));
    cout << ans[0] << "\n";
}

Subtask #1
0.0 / 0.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Incorrect 26 ms 340 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #2
0 / 7.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 0 ms 212 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
8.0 / 8.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct

Subtask #4
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 35 ms 340 KB Output is correct
8 Correct 45 ms 340 KB Output is correct
9 Correct 26 ms 340 KB Output is correct
10 Correct 28 ms 340 KB Output is correct
11 Correct 37 ms 340 KB Output is correct

Subtask #5
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 35 ms 340 KB Output is correct
8 Correct 45 ms 340 KB Output is correct
9 Correct 26 ms 340 KB Output is correct
10 Correct 28 ms 340 KB Output is correct
11 Correct 37 ms 340 KB Output is correct
12 Execution timed out 1075 ms 13672 KB Time limit exceeded
13 Halted 0 ms 0 KB -

Subtask #6
0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 35 ms 340 KB Output is correct
8 Correct 45 ms 340 KB Output is correct
9 Correct 26 ms 340 KB Output is correct
10 Correct 28 ms 340 KB Output is correct
11 Correct 37 ms 340 KB Output is correct
12 Correct 1 ms 212 KB Output is correct
13 Incorrect 32 ms 400 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #7
0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 35 ms 340 KB Output is correct
8 Correct 45 ms 340 KB Output is correct
9 Correct 26 ms 340 KB Output is correct
10 Correct 28 ms 340 KB Output is correct
11 Correct 37 ms 340 KB Output is correct
12 Execution timed out 1075 ms 13672 KB Time limit exceeded
13 Halted 0 ms 0 KB -

Subtask #8
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Incorrect 26 ms 340 KB Output isn't correct
3 Halted 0 ms 0 KB -