Submission #909956

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
909956	2024-01-17T16:41:05 Z	dsyz	Fountain (eJOI20_fountain)	C++17	100 / 100	118 ms	13352 KB

fountain

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define MAXN (1000005)
int main() {
	ios_base::sync_with_stdio(false);cin.tie(0);
	ll N,Q;
	cin>>N>>Q;
	pair<ll,ll> arr[N]; //dimater, capacity
	for(ll i = 0;i < N;i++){
		cin>>arr[i].first>>arr[i].second;
	}
	vector<pair<ll,pair<ll,ll> > > qu;
	for(ll q = 0;q < Q;q++){
		ll R,V;
		cin>>R>>V;
		R--;
		qu.push_back({R,{V,q}});
	}
	sort(qu.begin(),qu.end(),greater<pair<ll,pair<ll,ll> > >());
	ll ans[Q];
	ll ptr = N;
	deque<pair<pair<ll,ll>,ll> > dq;
	deque<ll> sufsum;
	for(ll q = 0;q < Q;q++){
		ll R = qu[q].first;
		ll V = qu[q].second.first;
		ll ind = qu[q].second.second;
		while(ptr >= 1 && ptr - 1 >= R){
			ptr--;
			while(!dq.empty() && dq.front().first.first <= arr[ptr].first){
				dq.pop_front();
				sufsum.pop_front();
			}
			dq.push_front({{arr[ptr].first,arr[ptr].second},ptr});
			if(sufsum.empty()) sufsum.push_front(arr[ptr].second);
			else sufsum.push_front(sufsum.front() + arr[ptr].second);
		}
		if(V > sufsum.front()){
			ans[ind] = 0; //flow of water ends in waterways
		}else{
			ll high = dq.size() - 1;
			ll low = -1;
			while(high - low > 1){ //binary search for minimum index with prefix sum >= V
				ll mid = (high + low) / 2;
				ll after = 0;
				if(mid < ll(sufsum.size()) - 1) after = sufsum[mid + 1];
				if(sufsum.front() - after >= V){
					high = mid;
				}else{
					low = mid;
				}
			}
			ans[ind] = dq[high].second + 1;
		}
	}
	for(ll q = 0;q < Q;q++){
		cout<<ans[q]<<'\n';
	}
}

Subtask #1

30.0 / 30.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	344 KB	Output is correct
2	Correct	1 ms	344 KB	Output is correct
3	Correct	1 ms	348 KB	Output is correct
4	Correct	1 ms	348 KB	Output is correct
5	Correct	1 ms	348 KB	Output is correct
6	Correct	1 ms	348 KB	Output is correct
7	Correct	1 ms	344 KB	Output is correct

Subtask #2

30.0 / 30.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	75 ms	9412 KB	Output is correct
2	Correct	84 ms	10848 KB	Output is correct

Subtask #3

40.0 / 40.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	344 KB	Output is correct
2	Correct	1 ms	344 KB	Output is correct
3	Correct	1 ms	348 KB	Output is correct
4	Correct	1 ms	348 KB	Output is correct
5	Correct	1 ms	348 KB	Output is correct
6	Correct	1 ms	348 KB	Output is correct
7	Correct	1 ms	344 KB	Output is correct
8	Correct	75 ms	9412 KB	Output is correct
9	Correct	84 ms	10848 KB	Output is correct
10	Correct	1 ms	344 KB	Output is correct
11	Correct	44 ms	5072 KB	Output is correct
12	Correct	118 ms	13352 KB	Output is correct
13	Correct	97 ms	10932 KB	Output is correct
14	Correct	80 ms	9912 KB	Output is correct
15	Correct	71 ms	10416 KB	Output is correct