Submission #1037053

#	Time	Username	Problem	Language	Result	Execution time	Memory
1037053		HappyCapybara	Sky Walking (IOI19_walk)	C++17	10 / 100	4056 ms	702616 KiB

walk

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

#define ll long long

ll 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(), m = l.size();
	vector<vector<pair<int,int>>> sws(n, {{0, m}});
	for (int i=0; i<m; i++){
		for (int j=l[i]; j<=r[i]; j++){
			if (y[i] <= h[j]) sws[j].push_back({y[i], i});
		}
	}
	y.push_back(0);
	for (int i=0; i<n; i++) sort(sws[i].begin(), sws[i].end());
	map<ll,vector<int>> pn;
	for (int i=0; i<n; i++){
		if (sws[i].size() == 0) continue;
		for (int j=0; j<sws[i].size(); j++){
			if (j < sws[i].size()-1) pn[i*100001+sws[i][j].second].push_back(sws[i][j+1].second);
			if (j > 0) pn[i*100001+sws[i][j].second].push_back(sws[i][j-1].second);
		}
	}
	priority_queue<vector<ll>> pq;
	unordered_set<ll> seen;
	pq.push({0, s, m});
	while (!pq.empty()){
		ll d = -pq.top()[0];
		int bld = pq.top()[1], sw = pq.top()[2];
		pq.pop();
		//cout << d << " " << bld << " " << sw << "\n";
		if (bld == g && sw == m) return d;
		if (seen.find(bld*100001+sw) != seen.end()) continue;
		seen.insert(bld*100001+sw);
		for (int next : pn[bld*100001+sw]) pq.push({-(d+abs(y[next]-y[sw])), bld, next});
		if (sw == m) continue;
		for (int next=l[sw]; next<=r[sw]; next++){
			if (next != bld && h[next] >= y[sw]) pq.push({-(d+abs(x[next]-x[bld])), next, sw});
		}
	}
	return -1;
}

Compilation message (stderr)

walk.cpp: In function 'long long int min_distance(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>, int, int)':
walk.cpp:20:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |   for (int j=0; j<sws[i].size(); j++){
      |                 ~^~~~~~~~~~~~~~
walk.cpp:21:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |    if (j < sws[i].size()-1) pn[i*100001+sws[i][j].second].push_back(sws[i][j+1].second);
      |        ~~^~~~~~~~~~~~~~~~~

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