Submission #1058297

#	Time	Username	Problem	Language	Result	Execution time	Memory
1058297		Unforgettablepl	Sky Walking (IOI19_walk)	C++17	10 / 100	4097 ms	1048576 KiB

walk

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

long long min_distance(vector<int> x,vector<int> h,vector<int> l,
					   vector<int> r,vector<int> y,int s,int g){
	int n = x.size();
	int m = l.size();
	vector<vector<pair<int,int>>> points(n);
	vector<vector<pair<int,int>>> adj(n);
	int S = n;
	for(int i=0;i<n;i++)points[i].emplace_back(i,0);
	vector<tuple<int,int,int>> skywalks;
	for(int i=0;i<m;i++)skywalks.emplace_back(y[i],l[i],r[i]);
	sort(skywalks.begin(), skywalks.end());
	auto add_point = [&](int x,int h) {
		adj.emplace_back();
		adj[S].emplace_back(points[x].back().first,h-points[x].back().second);
		adj[points[x].back().first].emplace_back(S,h-points[x].back().second);
		points[x].emplace_back(S,h);
		return S++;
	};
	for(int i=0;i<m;i++){
		auto [height,left,right] = skywalks[i];
		auto last_point = add_point(left,height);
		auto last_x = x[left];
		for(int j=left+1;j<=right;j++) {
			if(h[j]<height)continue;
			auto curr_point = add_point(j,height);
			adj[curr_point].emplace_back(last_point,x[j]-last_x);
			adj[last_point].emplace_back(curr_point,x[j]-last_x);
			last_point=curr_point;
			last_x=x[j];
		}
	}
	priority_queue<pair<long long,int>> q;
	vector<bool> visited(S);
	q.emplace(0,s);
	while(!q.empty()) {
		auto [dist,idx] = q.top();q.pop();dist=-dist;
		if(visited[idx])continue;
		visited[idx]=true;
		if(idx==g)return dist;
		for(auto&[v,c]:adj[idx])if(!visited[v])q.emplace(-dist-c,v);
	}
	return -1;
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 14
• Subtask 3: 0 / 15
• Subtask 4: 0 / 18
• Subtask 5: 0 / 43