Submission #536661

#	Time	Username	Problem	Language	Result	Execution time	Memory
536661		Gurban	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	36 / 100	1092 ms	45140 KiB

skyscraper

#include "bits/stdc++.h"
using namespace std;

using ll = long long;

const int maxn=3e4+5;
int n,m;
int b[maxn],p[maxn];
vector<int>v[maxn];
set<pair<int,int>>vis;
map<pair<int,int>,int>dis;

int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);

	cin >> n >> m;
	for(int i = 0;i < m;i++){
		cin >> b[i] >> p[i];
		v[b[i]].push_back(p[i]);
	}
	priority_queue<tuple<int,int,int>>q;
	q.push({0,b[0],p[0]});
	dis[{b[0],p[0]}] = 0;
	while(!q.empty()){
		int idx = get<1>(q.top());
		int pi = get<2>(q.top());
		q.pop();
		if(vis.find({idx,pi}) != vis.end()) continue;
		vis.insert({idx,pi});
		int now = dis[{idx,pi}];
		if(idx - pi >= 0){
			auto t = dis.find({idx - pi,pi});
			if(t == dis.end() or (t != dis.end() and (*t).second > now + 1)){
				dis[{idx - pi,pi}] = now + 1;
				q.push({-now - 1,idx - pi,pi});
			}
		}
		if(idx + pi < n){
			auto t = dis.find({idx + pi,pi});
			if(t == dis.end() or (t != dis.end() and (*t).second > now + 1)){
				dis[{idx + pi,pi}] = now + 1;
				q.push({-now - 1,idx + pi,pi});
			}
		}
		for(auto i : v[idx]){
			if(idx - i >= 0){
				auto t = dis.find({idx - i,i});
				if(t == dis.end() or (t != dis.end() and (*t).second > now + 1)){
					dis[{idx - i,i}] = now + 1;
					q.push({-now - 1,idx - i,i});
				}		
			}
			if(idx + i < n){
				auto t = dis.find({idx + i,i});
				if(t == dis.end() or (t != dis.end() and (*t).second > now + 1)){
					dis[{idx + i,i}] = now + 1;
					q.push({-now - 1,idx + i,i});
				}
			}
		}
	}
	int ans = 1e9;
	for(auto i : dis){
		if(i.first.first == b[1]){
			ans = min(ans,i.second);
		}
	}
	if(ans == 1e9) cout<<-1;
	else cout<<ans;
}

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 14 / 14
• Subtask 4: 0 / 21
• Subtask 5: 0 / 43