Submission #932344

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
932344	2024-02-23T08:30:35 Z	LucaIlie	Star Trek (CEOI20_startrek)	C++17	23 / 100	52 ms	11604 KB

startrek

#include <bits/stdc++.h>

#define int long long

using namespace std;

const int MAX_N = 1e5;
const int MAX_D = 1e5;
const int MOD = 1e9 + 7;
bool canWin[MAX_N + 1];
int countChildrenLosers[MAX_N + 1], add[MAX_N + 1], reach[MAX_N + 1], dp[MAX_D];
vector<int> adj[MAX_N + 1];

void dfsGame( int u, int p ) {
    canWin[u] = false;
    countChildrenLosers[u] = 0;
    for ( int v: adj[u] ) {
        if ( v == p )
            continue;
        dfsGame( v, u );
        canWin[u] |= (!canWin[v]);
        countChildrenLosers[u] += (!canWin[v]);
    }
}

void dfsCalcAdd( int u, int p ) {
    if ( p == 0 ) {
        add[u] = (canWin[u] ? -1 : 1);
        reach[u] = u;
    } else {
        if ( canWin[u] ) {
            if ( canWin[p] ) {
                add[u] = -1;
                reach[u] = u;
            } else {
                add[u] = add[p] - 1;
                reach[u] = reach[p];
            }
        } else {
            if ( countChildrenLosers[p] >= 2 ) {
                add[u] = 1;
                reach[u] = u;
            } else {
                add[u] = add[p] + 1;
                reach[u] = reach[p];
            }
        }
    }

    for ( int v: adj[u] ) {
        if ( v == p )
            continue;
        dfsCalcAdd( v, u );
    }
}

int lgPut( int x, int n ) {
    if ( n == 0 )
        return 1;

    int p = lgPut( x, n / 2 );
    p = (long long)p * p % MOD;
    if ( n % 2 == 1 )
        p = (long long)p * x % MOD;

    return p;
}

signed main() {
    int n, d;

    cin >> n >> d;

    for ( int i = 0; i < n - 1; i++ ) {
        int u, v;
        cin >> u >> v;
        adj[u].push_back( v );
        adj[v].push_back( u );
        adj[u + n].push_back( v + n );
        adj[v + n].push_back( u + n );
        adj[u + 2 * n].push_back( v + 2 * n );
        adj[v + 2 * n].push_back( u + 2 * n );
    }

    /*int an = 0;
    for ( int u = 1; u <= n; u++ ) {
        for ( int v = n + 1; v <= 2 * n; v++ ) {
            adj[u].push_back( v );
            adj[v].push_back( u );
            for ( int w = n + 1; w <= 2 * n; w++ ) {
                for ( int t = 2 * n + 1; t <= 3 * n; t++ ) {
                    adj[w].push_back( t );
                    adj[t].push_back( w );
                    dfsGame( 1, 0 );
                    if ( canWin[1] ) {
                        an++;
                        printf( "W %d-%d %d-%d\n", u, v, w, t );
                    }
                    adj[w].pop_back();
                    adj[t].pop_back();
                }
            }
            adj[u].pop_back();
            adj[v].pop_back();
        }
    }
    cout << an << "\n";*/

    int losers = 0, winners = 0, reach1Losers = 0, reach1Winners = 0;
    for ( int r = 1; r <= n; r++ ) {
        dfsGame( r, 0 );
        dfsCalcAdd( r, 0 );
        losers += !canWin[r];
        winners += canWin[r];
        for ( int v = 1; v <= n; v++ ) {
            reach1Losers += (!canWin[r] && !canWin[v] && reach[v] == 1);
            reach1Winners += (canWin[r] && !canWin[v] && reach[v] == 1);
        }
    }

    dp[0] = losers;
    for ( int i = 1; i < d; i++ )
        dp[i] = (losers * lgPut( n, 2 * i ) + (reach1Winners - reach1Losers + MOD) * dp[i - 1]) % MOD;

    dfsGame( 1, 0 );
    dfsCalcAdd( 1, 0 );

    //cout << dp[0] << " " << dp[1] << "\n";

    int ans = (canWin[1] ? 0 : lgPut( n, 2 * d ) );
    for ( int v = 1; v <= n; v++ ) {
        if ( canWin[1] ) {
            if ( !canWin[v] && reach[v] == 1 )
                ans = (ans + dp[d - 1]) % MOD;
        } else {
            if ( !canWin[v] && reach[v] == 1 )
                ans = (ans - dp[d - 1]) % MOD;
        }
    }

    cout << (lgPut( n, 2 * d ) - ans + MOD) % MOD << "\n";

    return 0;
}

Subtask #1
0.0 / 0.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	4700 KB	Output is correct
2	Incorrect	19 ms	4844 KB	Output isn't correct
3	Halted	0 ms	0 KB	-

Subtask #2
0 / 7.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	4696 KB	Output is correct
2	Correct	2 ms	4696 KB	Output is correct
3	Runtime error	52 ms	11604 KB	Execution killed with signal 11
4	Halted	0 ms	0 KB	-

Subtask #3
8.0 / 8.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	4700 KB	Output is correct
2	Correct	1 ms	4700 KB	Output is correct
3	Correct	1 ms	4700 KB	Output is correct
4	Correct	1 ms	4700 KB	Output is correct
5	Correct	1 ms	4700 KB	Output is correct
6	Correct	2 ms	4700 KB	Output is correct

Subtask #4
15.0 / 15.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	4700 KB	Output is correct
2	Correct	1 ms	4700 KB	Output is correct
3	Correct	1 ms	4700 KB	Output is correct
4	Correct	1 ms	4700 KB	Output is correct
5	Correct	1 ms	4700 KB	Output is correct
6	Correct	2 ms	4700 KB	Output is correct
7	Correct	27 ms	4700 KB	Output is correct
8	Correct	37 ms	4700 KB	Output is correct
9	Correct	16 ms	4700 KB	Output is correct
10	Correct	20 ms	4700 KB	Output is correct
11	Correct	20 ms	4700 KB	Output is correct

Subtask #5
0 / 15.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	4700 KB	Output is correct
2	Correct	1 ms	4700 KB	Output is correct
3	Correct	1 ms	4700 KB	Output is correct
4	Correct	1 ms	4700 KB	Output is correct
5	Correct	1 ms	4700 KB	Output is correct
6	Correct	2 ms	4700 KB	Output is correct
7	Correct	27 ms	4700 KB	Output is correct
8	Correct	37 ms	4700 KB	Output is correct
9	Correct	16 ms	4700 KB	Output is correct
10	Correct	20 ms	4700 KB	Output is correct
11	Correct	20 ms	4700 KB	Output is correct
12	Runtime error	4 ms	9052 KB	Execution killed with signal 11
13	Halted	0 ms	0 KB	-

Subtask #6
0 / 20.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	4700 KB	Output is correct
2	Correct	1 ms	4700 KB	Output is correct
3	Correct	1 ms	4700 KB	Output is correct
4	Correct	1 ms	4700 KB	Output is correct
5	Correct	1 ms	4700 KB	Output is correct
6	Correct	2 ms	4700 KB	Output is correct
7	Correct	27 ms	4700 KB	Output is correct
8	Correct	37 ms	4700 KB	Output is correct
9	Correct	16 ms	4700 KB	Output is correct
10	Correct	20 ms	4700 KB	Output is correct
11	Correct	20 ms	4700 KB	Output is correct
12	Correct	1 ms	4696 KB	Output is correct
13	Incorrect	19 ms	4700 KB	Output isn't correct
14	Halted	0 ms	0 KB	-

Subtask #7
0 / 20.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	4700 KB	Output is correct
2	Correct	1 ms	4700 KB	Output is correct
3	Correct	1 ms	4700 KB	Output is correct
4	Correct	1 ms	4700 KB	Output is correct
5	Correct	1 ms	4700 KB	Output is correct
6	Correct	2 ms	4700 KB	Output is correct
7	Correct	27 ms	4700 KB	Output is correct
8	Correct	37 ms	4700 KB	Output is correct
9	Correct	16 ms	4700 KB	Output is correct
10	Correct	20 ms	4700 KB	Output is correct
11	Correct	20 ms	4700 KB	Output is correct
12	Runtime error	4 ms	9052 KB	Execution killed with signal 11
13	Halted	0 ms	0 KB	-

Subtask #8
0 / 15.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	4700 KB	Output is correct
2	Incorrect	19 ms	4844 KB	Output isn't correct
3	Halted	0 ms	0 KB	-

Submission #932344

Compilation message