Submission #588795

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
588795	2022-07-04T05:14:51 Z	jiahng	Star Trek (CEOI20_startrek)	C++14	23 / 100	1000 ms	19804 KB

startrek

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
#define int ll
typedef pair<int32_t, int32_t> pi;
typedef vector <int> vi;
typedef vector <pi> vpi;
typedef pair<pi, ll> pii;
typedef set <ll> si;
typedef long double ld;
#define f first
#define s second
#define mp make_pair
#define FOR(i,s,e) for(int i=s;i<=int(e);++i)
#define DEC(i,s,e) for(int i=s;i>=int(e);--i)
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define lbd(x, y) lower_bound(all(x), y)
#define ubd(x, y) upper_bound(all(x), y)
#define aFOR(i,x) for (auto i: x)
#define mem(x,i) memset(x,i,sizeof x)
#define fast ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0)
#define maxn 400010
#define INF (ll)(1e9+10)
#define MOD 1000000007
typedef pair <vi, int> pvi;
typedef pair <int,pi> ipi;
typedef vector <pii> vpii;
typedef pair <pi,pi> pipi;

int N,D,a,b;
vi adj[maxn];

bool win[maxn];
int firstpar[maxn], depth[maxn];

void dfs(int x, int p){
	win[x] = 0;
	aFOR(i,adj[x]) if (i != p){
		depth[i] = depth[x] + 1; dfs(i,x);
		win[x] |= !win[i];
	}
}

void dfs2(int x,int p){
	if (p == -1) firstpar[x] = x;
	else{
		firstpar[x] = firstpar[p];
		aFOR(i, adj[p]) if (depth[i] == depth[x] && i != x && !win[i]){
			firstpar[x] = x;
		}
	}
	aFOR(i,adj[x]) if (i != p) dfs2(i,x);
}

int qexp(int a,int b){
	int ans = 1;
	while (b){
		if (b & 1) (ans *= a) %= MOD;
		(a *= a) %= MOD;
		b <<= 1;
	}
	return ans;
}
int32_t main(){
    fast;
    cin >> N >> D;
    FOR(i,1,N-1){
		cin >> a >> b; adj[a].pb(b); adj[b].pb(a);
	}
	
	int numnexte = 0,numnexto = 0, numwin = 0;
	
	int ans = 0;
	FOR(i,1,N){
		depth[i] = 0; dfs(i,-1); dfs2(i,-1);
		ans += win[i];
		int nnexte = 0,nnexto = 0, nwin = 0;
		FOR(j,1,N){
			if (win[j]) nwin++;
			else if (firstpar[j] == i){
				if (depth[1] % 2 == 0) nnexte++;
				else nnexto++;
			}else if ((depth[j] - depth[firstpar[j]]) % 2 == 1) nwin++;
		}
		numnexte += nnexte; numnexto += nnexto; numwin += nwin;
	}
	
	
	//~ cout << ans << '\n';
	DEC(j,D-1,1) ans = (((numnexto - numnexte) * ans) % MOD + (qexp(N, 2*(D-j)-1) * (numnexte + numwin)) % MOD) % MOD;
	//~ cout << (nnexto1 - nnexte1) * ans + nwin1 * N + qexp(N, 2*D-1)* nnexte1;
	int x = ans; ans = 0;
	FOR(i,1,N){
		depth[i] = 0; dfs(i,-1); dfs2(i,-1);
		if (win[1]) (ans += N) %= MOD;
		else if (firstpar[1] == i){
			if (depth[1] % 2 == 0) (ans += N - x) %= MOD;
			else (ans += x) %= MOD;
		}else if ((depth[1] - depth[firstpar[1]]) % 2 == 1) (ans += N) %= MOD;
		
	}
	cout << ans;
}

Subtask #1
0.0 / 0.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	7 ms	9684 KB	Output is correct
2	Incorrect	91 ms	9684 KB	Output isn't correct
3	Halted	0 ms	0 KB	-

Subtask #2
0 / 7.0

#	Verdict	Execution time	Memory	Grader output
1	Incorrect	5 ms	9716 KB	Output isn't correct
2	Halted	0 ms	0 KB	-

Subtask #3
8.0 / 8.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	6 ms	9700 KB	Output is correct
2	Correct	6 ms	9684 KB	Output is correct
3	Correct	6 ms	9720 KB	Output is correct
4	Correct	8 ms	9700 KB	Output is correct
5	Correct	6 ms	9684 KB	Output is correct
6	Correct	7 ms	9684 KB	Output is correct

Subtask #4
15.0 / 15.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	6 ms	9700 KB	Output is correct
2	Correct	6 ms	9684 KB	Output is correct
3	Correct	6 ms	9720 KB	Output is correct
4	Correct	8 ms	9700 KB	Output is correct
5	Correct	6 ms	9684 KB	Output is correct
6	Correct	7 ms	9684 KB	Output is correct
7	Correct	82 ms	9812 KB	Output is correct
8	Correct	92 ms	9808 KB	Output is correct
9	Correct	616 ms	9780 KB	Output is correct
10	Correct	83 ms	9784 KB	Output is correct
11	Correct	89 ms	9780 KB	Output is correct

Subtask #5
0 / 15.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	6 ms	9700 KB	Output is correct
2	Correct	6 ms	9684 KB	Output is correct
3	Correct	6 ms	9720 KB	Output is correct
4	Correct	8 ms	9700 KB	Output is correct
5	Correct	6 ms	9684 KB	Output is correct
6	Correct	7 ms	9684 KB	Output is correct
7	Correct	82 ms	9812 KB	Output is correct
8	Correct	92 ms	9808 KB	Output is correct
9	Correct	616 ms	9780 KB	Output is correct
10	Correct	83 ms	9784 KB	Output is correct
11	Correct	89 ms	9780 KB	Output is correct
12	Execution timed out	1090 ms	19804 KB	Time limit exceeded
13	Halted	0 ms	0 KB	-

Subtask #6
0 / 20.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	6 ms	9700 KB	Output is correct
2	Correct	6 ms	9684 KB	Output is correct
3	Correct	6 ms	9720 KB	Output is correct
4	Correct	8 ms	9700 KB	Output is correct
5	Correct	6 ms	9684 KB	Output is correct
6	Correct	7 ms	9684 KB	Output is correct
7	Correct	82 ms	9812 KB	Output is correct
8	Correct	92 ms	9808 KB	Output is correct
9	Correct	616 ms	9780 KB	Output is correct
10	Correct	83 ms	9784 KB	Output is correct
11	Correct	89 ms	9780 KB	Output is correct
12	Correct	5 ms	9684 KB	Output is correct
13	Incorrect	99 ms	9684 KB	Output isn't correct
14	Halted	0 ms	0 KB	-

Subtask #7
0 / 20.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	6 ms	9700 KB	Output is correct
2	Correct	6 ms	9684 KB	Output is correct
3	Correct	6 ms	9720 KB	Output is correct
4	Correct	8 ms	9700 KB	Output is correct
5	Correct	6 ms	9684 KB	Output is correct
6	Correct	7 ms	9684 KB	Output is correct
7	Correct	82 ms	9812 KB	Output is correct
8	Correct	92 ms	9808 KB	Output is correct
9	Correct	616 ms	9780 KB	Output is correct
10	Correct	83 ms	9784 KB	Output is correct
11	Correct	89 ms	9780 KB	Output is correct
12	Execution timed out	1090 ms	19804 KB	Time limit exceeded
13	Halted	0 ms	0 KB	-

Subtask #8
0 / 15.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	7 ms	9684 KB	Output is correct
2	Incorrect	91 ms	9684 KB	Output isn't correct
3	Halted	0 ms	0 KB	-

Submission #588795

Compilation message