Submission #1292954

#	Time	Username	Problem	Language	Result	Execution time	Memory
1292954		thdh__	Sumtree (INOI20_sumtree)	C++20	10 / 100	228 ms	28628 KiB

Main

#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define eb emplace_back
#define pu push
#define ins insert
#define fi first
#define se second
#define all(a) a.begin(),a.end()
#define bruh ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define fu(x,a,b) for (auto x=a;x<=b;x++)
#define fd(x,a,b) for (auto x=a;x>=b;x--)
#define int ll

using namespace std;
//mt19937 mt(chrono::steady_clock::now().time_since_epoch().count());

/*
Competitive Programming notes that I need to study & fix my dumbass self:

1. Coding:
- Always be sure to check the memory of arrays (maybe use vectors), for loops
- Always try to maximize the memory if possible, even if you are going for subtasks
- Do not exploit #define int long long, it will kill you

2. Stress: 
- Always try generating big testcases and try if they run

3. Time management:
- Don't overcommit or undercommit, always spend a certain amount of time to think a problem, don't just look at it and say I'm fucked
- Do not spend too much time coding brute-force solutions, they should be easily-codable solutions that don't take up too much time

Time management schedule:
Offline / LAH days (4 problems - 3h):
15' thinking of solution / idea
1. no idea: skip
2. yes idea: continue thinking for <= 15'

+ implementing: <= 20'
+ brute-force: <= 5'
+ test generator: <= 5'

I hate offline because I am dumb
*/

typedef pair<int, int> ii;
const int N = 1e6+5;
const int B = 750;
const int mod = 1e9+7;
const int inf = 1e18;
using cd = complex<double>;
const long double PI = acos(-1);
int power(int a,int b) {ll x = 1;if (a >= mod) a%=mod; while (b) {if (b & 1) x = x*a % mod;a = a*a % mod;b>>=1;}return x;} 

int n,r,q;
vector<int> adj[N];

int gt[N], inv[N];

void precalc() 
{
	gt[0] = 1;
	for (int i = 1; i < N; i++) gt[i] = (gt[i-1] * i) % mod;
	inv[N-1] = power(gt[N-1], mod-2);
	for (int i = N-2; i >= 0; i--) inv[i] = (inv[i+1] * (i+1)) % mod;
}

int C(int n, int k) 
{
	if (k > n) return 0;
	if (k == n || !k) return 1;
	return (gt[n] * inv[k] % mod) * inv[n-k] % mod;
}

void solve()
{
	precalc();
	cin>>n>>r;
	for (int i = 1; i < n; i++) 
	{
		int u,v;
		cin>>u>>v;
		adj[u].pb(v); adj[v].pb(u);
	}
	if (n == 1) 
	{
		cout<<1<<endl;
		cin>>q;
		while (q--) 
		{
			cout<<1<<endl;
		}
		return;
	}
	int ans = 0;
	for (int i = 0; i <= r; i++) 
	{
		ans += C((n-1) + i - 1, (n-1)-1), ans %= mod;
	}
	cout<<ans<<endl;
	cin>>q;
	while (q--) 
	{
		int tp, u;
		cin>>tp>>u;
		if (tp == 1) 
		{
			int v;
			cin>>v;
		} else 
		{
			
		}
		cout<<0<<endl;
	}
}

/*
Go through the mistakes you usually make and revise your code, for god's sake...
*/

signed main()
{
	bruh
	//freopen(".inp","r",stdin);
	//freopen(".out","w",stdout);
	int t = 1;
	// cin>>t;
	while (t--)
	{
		solve();
		cout<<"\n";
	}
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 20
• Subtask 3: 0 / 20
• Subtask 4: 0 / 20
• Subtask 5: 0 / 30