Submission #416752

#	Time	Username	Problem	Language	Result	Execution time	Memory
416752		peuch	Sky Walking (IOI19_walk)	C++17	0 / 100	25 ms	7044 KiB

walk

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

const long long MAXN = 1e5 + 10;
const long long INF = 1e18;

map<pair<long long, long long>, long long> node;
pair<int, int> uncomp[MAXN];
vector<long long> dist;
vector<bool> marc;
vector<vector<long long> > ar, wg;
long long cnt = -1;

struct event{
	long long l, r, h;
	event(long long _l = 0, long long _r = 0, long long _h = 0){
		l = _l, r = _r, h = _h;
	}
	bool operator < (event x) const {
		if(h == x.h) return r - l < x.r - x.l;
		return h > x.h;	
	}
};

vector<event> line;
vector<long long> last;

void dijkstra(long long ini);

int create(int x, int y){
	if(node[make_pair(x, y)] != 0) return node[make_pair(x, y)];
	node[make_pair(x, y)] = ++cnt;
	uncomp[cnt] = make_pair(x, y);
	ar.push_back(vector<long long>(0));
	wg.push_back(vector<long long>(0));
	dist.push_back(INF);
	marc.push_back(0);
	if(last[x] != 0) {
		ar[node[make_pair(x, y)]].push_back(node[make_pair(x, last[x])]);
		ar[node[make_pair(x, last[x])]].push_back(node[make_pair(x, y)]);
		wg[node[make_pair(x, y)]].push_back(abs(y - last[x]));
		wg[node[make_pair(x, last[x])]].push_back(abs(y - last[x]));
	}
	last[x] = y;
}

long long min_distance(std::vector<int> X, std::vector<int> H, std::vector<int> L, std::vector<int> R, std::vector<int> Y, int S, int G) {
	
	for(long long i = 0; i < X.size(); i++)
		line.push_back(event(i, i, H[i]));
	
	for(long long i = 0; i < L.size(); i++)
		line.push_back(event(L[i], R[i], Y[i]));
	
	sort(line.begin(), line.end());
	last = vector<long long> (X.size(), 0);
	
	set<long long> torres;
	for(long long i = 0; i < line.size(); i++){
		long long l = line[i].l, r = line[i].r, y = line[i].h;
		if(l == r) torres.insert(l);
		else{
			set<long long> :: iterator it = torres.upper_bound(l);
			create(l, y);
			long long ult = l;
			while(it != torres.end() && *it <= r){
				create(*it, y);
				ar[node[make_pair(*it, y)]].push_back(node[make_pair(ult, y)]);
				ar[node[make_pair(ult, y)]].push_back(node[make_pair(*it, y)]);
				wg[node[make_pair(*it, y)]].push_back(abs(X[*it] - X[ult]));
				wg[node[make_pair(ult, y)]].push_back(abs(X[*it] - X[ult]));
				ult = *it;
				it++;
			}
		}
	}
	for(long long i = 0; i < X.size(); i++)
		create(i, 0);
	dijkstra(create(S, 0));
	if(dist[create(G, 0)] >= INF) dist[create(G, 0)] = -1;
	return dist[create(G, 0)];
}

void dijkstra(long long ini){
	dist[ini] = 0;
	set<pair<long long, long long> > s;
	for(long long i = 0; i <= cnt; i++)
		s.insert(make_pair(dist[i], i));
	while(!s.empty()){
		long long cur = s.begin()->second;
		if(dist[cur] >= INF) break;
		marc[cur] = 1;
		printf("Dist of %d %d is %lld\n", uncomp[cur].first, uncomp[cur].second, dist[cur]);
		s.erase(s.begin());
		for(long long i = 0; i < ar[cur].size(); i++){
			long long viz = ar[cur][i];
			if(marc[viz]) continue;
			s.erase(make_pair(dist[viz], viz));
			dist[viz] = min(dist[viz], dist[cur] + wg[cur][i]);
			s.insert(make_pair(dist[viz], viz));
		}
	}
}

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:50:25: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   50 |  for(long long i = 0; i < X.size(); i++)
      |                       ~~^~~~~~~~~~
walk.cpp:53:25: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |  for(long long i = 0; i < L.size(); i++)
      |                       ~~^~~~~~~~~~
walk.cpp:60:25: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<event>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   60 |  for(long long i = 0; i < line.size(); i++){
      |                       ~~^~~~~~~~~~~~~
walk.cpp:78:25: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   78 |  for(long long i = 0; i < X.size(); i++)
      |                       ~~^~~~~~~~~~
walk.cpp: In function 'void dijkstra(long long int)':
walk.cpp:96:26: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   96 |   for(long long i = 0; i < ar[cur].size(); i++){
      |                        ~~^~~~~~~~~~~~~~~~
walk.cpp: In function 'int create(int, int)':
walk.cpp:45:10: warning: control reaches end of non-void function [-Wreturn-type]
   45 |  last[x] = y;

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