Submission #1175294

#	Time	Username	Problem	Language	Result	Execution time	Memory
1175294		KluydQ	Fountain (eJOI20_fountain)	C++20	100 / 100	445 ms	36032 KiB

fountain

#include <bits/stdc++.h>
 
#define respagold ios_base::sync_with_stdio(0), cin.tie(0);
#define int long long
#define ll long long
#define int2 __int128_t
#define FOR( i, x, n, d ) for( int i = x; i <= n; i += d )
#define FORR( i, x, n, d ) for( int i = x; i >= n; i -= d )
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define sz(x) (int)(x.size())
#define pb push_back
#define ins insert
#define lb lower_bound
#define ub upper_bound
#define pii pair <int, int>
#define mkp make_pair
 
using namespace std;
 
const int N = 2e5 + 123;
const int inf = 1e18;
const int mod = 1e9 + 7;
const double eps = 1e-13;
 
int a[N], b[N], c[N], n, m, q, k, x, y, w, l, r, up[N][20], di[N][20];
 
mt19937 rng( chrono::steady_clock::now().time_since_epoch().count());
 
int rand( int l, int r )
{
    uniform_int_distribution <int> uid( l, r );
    return uid( rng );
}
void solve()
{
	cin >> n >> m;
	FOR( i, 1, n, 1 ) cin >> a[i] >> b[i];
	
	stack <int> st;
	
	FORR( i, n, 1, 1 )
	{
		while( !st.empty() && a[st.top()] <= a[i] ) st.pop();
		c[i] = ( sz(st) ? st.top() : 0 ), st.push(i);
		up[i][0] = c[i], di[i][0] = b[i];
	}
	FOR( j, 1, 18, 1 )
	{
		FOR( i, 1, n, 1 )
		{
			up[i][j] = up[up[i][j - 1]][j - 1];
			di[i][j] = di[up[i][j - 1]][j - 1] + di[i][j - 1];
		}
	}
	FOR( bobek, 1, m, 1 )
	{
		cin >> x >> y;
		swap(x, y);
		
		int l = 0, r = n, res = -1;
		
		while( l <= r )
		{
			int md = l + r >> 1, v = y, sum = 0;
			
			FORR( i, 18, 0, 1 )
			{
				if( (md >> i) & 1 ) sum += di[v][i], v = up[v][i];
			}
			if( !v )
			{
				r = md - 1;
				continue;
			}
			if( sum + b[v] < x ) l = md + 1;
			else r = md - 1, res = md;
		}
		if( res == -1 )
		{
			cout << "0\n";
			continue;
		}
		int ans = y;
		FORR( i, 18, 0, 1 ) if( (res >> i) & 1 ) ans = up[ans][i];
		cout << ans << '\n';
	}
}
signed main()
{
//	freopen("connect.in", "r", stdin);
//	freopen("connect.out", "w", stdout);
	    
    respagold
    
    int test = 1;
    
    if( !test ) cin >> test;
	
	while( test -- )
	{
		solve();
	}
}
// solved by KluydQ

• Subtask 1: 30 / 30
• Subtask 2: 30 / 30
• Subtask 3: 40 / 40