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Submission #600106

# Submission time Handle Problem Language Result Execution time Memory
600106 2022-07-20T13:05:49 Z jasmin Star Trek (CEOI20_startrek) C++17
30 / 100
 1000 ms 13676 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

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Incorrect 30 ms 396 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #2
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 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 0 ms 212 KB Output is correct

Subtask #3
8.0 / 8.0

# Verdict Execution time Memory 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 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory 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 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 38 ms 340 KB Output is correct
8 Correct 43 ms 340 KB Output is correct
9 Correct 23 ms 396 KB Output is correct
10 Correct 31 ms 340 KB Output is correct
11 Correct 38 ms 340 KB Output is correct

Subtask #5
0 / 15.0

# Verdict Execution time Memory 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 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 38 ms 340 KB Output is correct
8 Correct 43 ms 340 KB Output is correct
9 Correct 23 ms 396 KB Output is correct
10 Correct 31 ms 340 KB Output is correct
11 Correct 38 ms 340 KB Output is correct
12 Execution timed out 1085 ms 13676 KB Time limit exceeded
13 Halted 0 ms 0 KB -

Subtask #6
0 / 20.0

# Verdict Execution time Memory 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 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 38 ms 340 KB Output is correct
8 Correct 43 ms 340 KB Output is correct
9 Correct 23 ms 396 KB Output is correct
10 Correct 31 ms 340 KB Output is correct
11 Correct 38 ms 340 KB Output is correct
12 Correct 0 ms 212 KB Output is correct
13 Incorrect 27 ms 392 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #7
0 / 20.0

# Verdict Execution time Memory 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 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 38 ms 340 KB Output is correct
8 Correct 43 ms 340 KB Output is correct
9 Correct 23 ms 396 KB Output is correct
10 Correct 31 ms 340 KB Output is correct
11 Correct 38 ms 340 KB Output is correct
12 Execution timed out 1085 ms 13676 KB Time limit exceeded
13 Halted 0 ms 0 KB -

Subtask #8
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Incorrect 30 ms 396 KB Output isn't correct
3 Halted 0 ms 0 KB -