Submission #932338

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
932338	2024-02-23T08:27:09 Z	LucaIlie	Star Trek (CEOI20_startrek)	C++17	23 / 100	1000 ms	15444 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;
    if ( d <= MAX_D )
    for ( int i = 1; i < d; i++ )
        dp[i] = (losers * lgPut( n, 2 * d ) + (reach1Winners - reach1Losers + MOD) * dp[i - 1]) % MOD;

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

    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	3 ms	4696 KB	Output is correct
2	Incorrect	21 ms	4708 KB	Output isn't correct
3	Halted	0 ms	0 KB	-

Subtask #2
0 / 7.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	2 ms	4696 KB	Output is correct
2	Correct	2 ms	4700 KB	Output is correct
3	Runtime error	5 ms	9052 KB	Execution killed with signal 7
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	2 ms	4700 KB	Output is correct
5	Correct	1 ms	4700 KB	Output is correct
6	Correct	1 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	2 ms	4700 KB	Output is correct
5	Correct	1 ms	4700 KB	Output is correct
6	Correct	1 ms	4700 KB	Output is correct
7	Correct	24 ms	4700 KB	Output is correct
8	Correct	33 ms	4700 KB	Output is correct
9	Correct	15 ms	4696 KB	Output is correct
10	Correct	20 ms	4700 KB	Output is correct
11	Correct	19 ms	4696 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	2 ms	4700 KB	Output is correct
5	Correct	1 ms	4700 KB	Output is correct
6	Correct	1 ms	4700 KB	Output is correct
7	Correct	24 ms	4700 KB	Output is correct
8	Correct	33 ms	4700 KB	Output is correct
9	Correct	15 ms	4696 KB	Output is correct
10	Correct	20 ms	4700 KB	Output is correct
11	Correct	19 ms	4696 KB	Output is correct
12	Execution timed out	1069 ms	15444 KB	Time limit exceeded
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	2 ms	4700 KB	Output is correct
5	Correct	1 ms	4700 KB	Output is correct
6	Correct	1 ms	4700 KB	Output is correct
7	Correct	24 ms	4700 KB	Output is correct
8	Correct	33 ms	4700 KB	Output is correct
9	Correct	15 ms	4696 KB	Output is correct
10	Correct	20 ms	4700 KB	Output is correct
11	Correct	19 ms	4696 KB	Output is correct
12	Correct	1 ms	4700 KB	Output is correct
13	Incorrect	18 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	2 ms	4700 KB	Output is correct
5	Correct	1 ms	4700 KB	Output is correct
6	Correct	1 ms	4700 KB	Output is correct
7	Correct	24 ms	4700 KB	Output is correct
8	Correct	33 ms	4700 KB	Output is correct
9	Correct	15 ms	4696 KB	Output is correct
10	Correct	20 ms	4700 KB	Output is correct
11	Correct	19 ms	4696 KB	Output is correct
12	Execution timed out	1069 ms	15444 KB	Time limit exceeded
13	Halted	0 ms	0 KB	-

Subtask #8
0 / 15.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	3 ms	4696 KB	Output is correct
2	Incorrect	21 ms	4708 KB	Output isn't correct
3	Halted	0 ms	0 KB	-

Submission #932338

Compilation message