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Submission #600209

# Submission time Handle Problem Language Result Execution time Memory
600209 2022-07-20T14:23:40 Z jasmin Star Trek (CEOI20_startrek) C++17
30 / 100
 1000 ms 14828 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 lose=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]){
        lose++;
    } 

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

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

    if(win_down[v]==0){
        redforce++;
        for(auto u: adi[v]){
            if(u!=p) dfs_redforce(u, v, adi);
        }
    }
    else if(win_down[v]==1){
        dfs_redforce(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=0; int r1=0;
    for(int i=n-1; i>=0; i--){
        lose=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_redforce(i, -1, adi);

        if(we_win){
            g1=n;
            r1=n-redforce;
        }
        else{
            g1=0;
            r1=redforce;
        }
        G+=g1;
        R+=r1;
    }

    matrix m1={g1, r1, 0, 0};
    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);
    vector<int> ans=mul(m1, mul(p, {n-lose, lose}));
    cout << ans[0] << "\n";
}

Subtask #1
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Incorrect 26 ms 408 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 0 ms 320 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 320 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 1 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 1 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 1 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 1 ms 212 KB Output is correct
7 Correct 36 ms 340 KB Output is correct
8 Correct 42 ms 468 KB Output is correct
9 Correct 23 ms 440 KB Output is correct
10 Correct 32 ms 340 KB Output is correct
11 Correct 33 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 1 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 1 ms 212 KB Output is correct
7 Correct 36 ms 340 KB Output is correct
8 Correct 42 ms 468 KB Output is correct
9 Correct 23 ms 440 KB Output is correct
10 Correct 32 ms 340 KB Output is correct
11 Correct 33 ms 340 KB Output is correct
12 Execution timed out 1073 ms 14828 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 1 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 1 ms 212 KB Output is correct
7 Correct 36 ms 340 KB Output is correct
8 Correct 42 ms 468 KB Output is correct
9 Correct 23 ms 440 KB Output is correct
10 Correct 32 ms 340 KB Output is correct
11 Correct 33 ms 340 KB Output is correct
12 Correct 0 ms 212 KB Output is correct
13 Incorrect 26 ms 340 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 1 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 1 ms 212 KB Output is correct
7 Correct 36 ms 340 KB Output is correct
8 Correct 42 ms 468 KB Output is correct
9 Correct 23 ms 440 KB Output is correct
10 Correct 32 ms 340 KB Output is correct
11 Correct 33 ms 340 KB Output is correct
12 Execution timed out 1073 ms 14828 KB Time limit exceeded
13 Halted 0 ms 0 KB -

Subtask #8
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Incorrect 26 ms 408 KB Output isn't correct
3 Halted 0 ms 0 KB -