Submission #588797

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
588797	2022-07-04T05:15:38 Z	jiahng	Star Trek (CEOI20_startrek)	C++14	23 / 100	1000 ms	19644 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;
	(ans += 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	6 ms	9712 KB	Output is correct
2	Incorrect	105 ms	9776 KB	Output isn't correct
3	Halted	0 ms	0 KB	-

Subtask #2
0 / 7.0

#	Verdict	Execution time	Memory	Grader output
1	Incorrect	6 ms	9704 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	5 ms	9708 KB	Output is correct
2	Correct	6 ms	9684 KB	Output is correct
3	Correct	7 ms	9728 KB	Output is correct
4	Correct	8 ms	9684 KB	Output is correct
5	Correct	6 ms	9684 KB	Output is correct
6	Correct	7 ms	9672 KB	Output is correct

Subtask #4
15.0 / 15.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	5 ms	9708 KB	Output is correct
2	Correct	6 ms	9684 KB	Output is correct
3	Correct	7 ms	9728 KB	Output is correct
4	Correct	8 ms	9684 KB	Output is correct
5	Correct	6 ms	9684 KB	Output is correct
6	Correct	7 ms	9672 KB	Output is correct
7	Correct	102 ms	9856 KB	Output is correct
8	Correct	90 ms	9832 KB	Output is correct
9	Correct	714 ms	9776 KB	Output is correct
10	Correct	95 ms	9776 KB	Output is correct
11	Correct	91 ms	9772 KB	Output is correct

Subtask #5
0 / 15.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	5 ms	9708 KB	Output is correct
2	Correct	6 ms	9684 KB	Output is correct
3	Correct	7 ms	9728 KB	Output is correct
4	Correct	8 ms	9684 KB	Output is correct
5	Correct	6 ms	9684 KB	Output is correct
6	Correct	7 ms	9672 KB	Output is correct
7	Correct	102 ms	9856 KB	Output is correct
8	Correct	90 ms	9832 KB	Output is correct
9	Correct	714 ms	9776 KB	Output is correct
10	Correct	95 ms	9776 KB	Output is correct
11	Correct	91 ms	9772 KB	Output is correct
12	Execution timed out	1083 ms	19644 KB	Time limit exceeded
13	Halted	0 ms	0 KB	-

Subtask #6
0 / 20.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	5 ms	9708 KB	Output is correct
2	Correct	6 ms	9684 KB	Output is correct
3	Correct	7 ms	9728 KB	Output is correct
4	Correct	8 ms	9684 KB	Output is correct
5	Correct	6 ms	9684 KB	Output is correct
6	Correct	7 ms	9672 KB	Output is correct
7	Correct	102 ms	9856 KB	Output is correct
8	Correct	90 ms	9832 KB	Output is correct
9	Correct	714 ms	9776 KB	Output is correct
10	Correct	95 ms	9776 KB	Output is correct
11	Correct	91 ms	9772 KB	Output is correct
12	Correct	7 ms	9684 KB	Output is correct
13	Incorrect	106 ms	9776 KB	Output isn't correct
14	Halted	0 ms	0 KB	-

Subtask #7
0 / 20.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	5 ms	9708 KB	Output is correct
2	Correct	6 ms	9684 KB	Output is correct
3	Correct	7 ms	9728 KB	Output is correct
4	Correct	8 ms	9684 KB	Output is correct
5	Correct	6 ms	9684 KB	Output is correct
6	Correct	7 ms	9672 KB	Output is correct
7	Correct	102 ms	9856 KB	Output is correct
8	Correct	90 ms	9832 KB	Output is correct
9	Correct	714 ms	9776 KB	Output is correct
10	Correct	95 ms	9776 KB	Output is correct
11	Correct	91 ms	9772 KB	Output is correct
12	Execution timed out	1083 ms	19644 KB	Time limit exceeded
13	Halted	0 ms	0 KB	-

Subtask #8
0 / 15.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	6 ms	9712 KB	Output is correct
2	Incorrect	105 ms	9776 KB	Output isn't correct
3	Halted	0 ms	0 KB	-

Submission #588797

Compilation message