Submission #833781

#	Time	Username	Problem	Language	Result	Execution time	Memory
833781		algorithm16	Race (IOI11_race)	C++14	43 / 100	244 ms	60396 KiB

race

#include<iostream>
#include<vector>
#include<set>
#include<algorithm>
#include "race.h"
using namespace std;
typedef long long int llint;
vector <pair<int,int> > v[200005];
set <pair<llint,llint> > s[200005];
llint k1,mn=1e9;
void f(int x,int y,llint dd,llint ll) {
	if(s[x].size()<s[y].size()) swap(s[x],s[y]);
	for(set <pair<llint,llint> >::iterator it=s[y].begin();it!=s[y].end();) {
		llint l=(*it).first,d=(*it).second;
		l-=ll;
		d-=dd;
		set <pair<llint,llint> >::iterator it2=s[x].lower_bound(make_pair(k1-l+ll,-1));
		if(it2!=s[x].end() && (*it2).first==k1-l+ll) mn=min(mn,d+(*it2).second-dd);
		it2=s[x].lower_bound(make_pair(l+ll,-1));
		if(it2==s[x].end() || (*it2).first!=l+ll) s[x].insert((*it));
		else if((*it2).second>(*it).second) {
			s[x].erase(it2);
			s[x].insert((*it));
		}
		it=s[y].erase(it);
	}
}
void dfs(int x,int p,llint d,llint l) {
	s[x].insert(make_pair(l,d));
	for(int i=0;i<v[x].size();i++) {
		if(v[x][i].first==p) continue;
		dfs(v[x][i].first,x,d+1,l+v[x][i].second);
		f(x,v[x][i].first,d,l);
	}
}
int best_path(int n,int k,int h[][2],int l[])
{
	k1=k;
	for(int i=0;i<n-1;i++) {
		v[h[i][0]].push_back(make_pair(h[i][1],l[i]));
		v[h[i][1]].push_back(make_pair(h[i][0],l[i]));
	}
	dfs(0,0,0,0);
	if(mn==1e9) mn=-1;
	return mn;
}
/*int main()
{
	int n,k;
	cin >> n >> k;
	for(int i=0;i<n-1;i++) {
		int a,b,l1;
		cin >> a >> b >> l1;
		h[i][0]=a;
		h[i][1]=b;
		l[i]=l1;
	}
	cout << best_path(n,k);
}
*/

Compilation message (stderr)

race.cpp: In function 'void dfs(int, int, llint, llint)':
race.cpp:30:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |  for(int i=0;i<v[x].size();i++) {
      |              ~^~~~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 12 / 12
• Subtask 3: 22 / 22
• Subtask 4: 0 / 57