Submission #769911

#	Time	Username	Problem	Language	Result	Execution time	Memory
769911		TimDee	Fountain (eJOI20_fountain)	C++17	0 / 100	180 ms	31684 KiB

fountain

//  Esti <3

//\
     šťastia pre nás :)
//   you're already the best
//             _
//   ^ ^      //
// >(O_O)<___//
//   \ __ __  \
//    \\ \\ \\\\
 
#include <bits/stdc++.h>
using namespace std;
 
//#pragma GCC optimize("O3","unroll-loops")
//#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
 
#pragma GCC optimize("O3")
#pragma GCC target("popcnt")

using ll = long long;
#define int long long
#define forn(i,n) for(int i=0; i<(n); ++i)
#define pb push_back
#define pi pair<int,int>
#define f first
#define s second 
#define vii(a,n) vector<int> a(n); forn(i,n) cin>>a[i];
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
 
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
const int inf = 1e18;
const int mod = 1e9+7;//998244353;
 
// \
\
:smiling_face_with_3_hearts: :smiling_face_with_3_hearts:  :smiling_face_with_3_hearts:  
 
//vidime sa veľmi skoro, moje slnko

const int N=1e5+5;
const int K=18;

int go[N][K];
int up[N][K];

void solve() {

	int n, q; cin>>n>>q;
	vector<pi> a(n);
	forn(i,n) cin>>a[i].f>>a[i].s;
	vector<int> to(n);
	vector<pi> st;
	st.pb({inf,-1});
	for(int i=n-1; i>=0; --i) {
		while (a[i].f >= st.back().f) st.pop_back();
		to[i]=st.back().s;
		st.pb({a[i].f,i});
	}
	forn(i,n) go[i][0]=a[i].s;// + (to[i]!=-1)?a[to[i]].s:inf;
	forn(i,n) up[i][0]=to[i];

	const int inf=2e9;
	for (int j=1; j<K; ++j) {
		forn(i,n) go[i][j]=go[i][j-1]+((up[i][j-1]!=-1)?go[up[i][j-1]][j-1]:inf);
		forn(i,n) up[i][j]=(up[i][j-1]!=-1)?up[up[i][j-1]][j-1]:up[i][j-1];
	}

	forn(j,4) {
		//forn(i,n) cout<<go[i][j]<<' '; cout<<'\n';
	}
	//cout<<'\n';
	forn(j,4) {
		//forn(i,n) cout<<up[i][j]<<' '; cout<<'\n';
	}

	forn(i,q) {
		int r,v; cin>>r>>v; --r;
		if (a[r].s >= v) {
			cout<<r+1<<'\n'; continue;
		} 
		int z=0;
		for (int j=K-1; j>=0; --j) {
			if (r==-1) continue;
			if (go[r][j] > v) continue;
			//cout<<"! "<<r<<' '<<j<<' '<<v<<' '<<go[r][j]<<' '<<up[r][j]<<'\n';
			v-=go[r][j];
			r=up[r][j];
			//cout<<r<<' '<<v<<'\n';
		}
		//if (v) cout<<to[v]+1<<'\n';
		//else 
			cout<<r+1<<'\n';
	}	

}

int32_t main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    int t=1;
    //cin>>t;
    while (t--) solve();
    return 0;
}

Compilation message (stderr)

fountain.cpp:3:1: warning: multi-line comment [-Wcomment]
    3 | //\
      | ^
fountain.cpp:9:1: warning: multi-line comment [-Wcomment]
    9 | //   \ __ __  \
      | ^
fountain.cpp:36:1: warning: multi-line comment [-Wcomment]
   36 | // \
      | ^
fountain.cpp: In function 'void solve()':
fountain.cpp:83:7: warning: unused variable 'z' [-Wunused-variable]
   83 |   int z=0;
      |       ^

• Subtask 1: 0 / 30
• Subtask 2: 0 / 30
• Subtask 3: 0 / 40