Submission #139038

#	Time	Username	Problem	Language	Result	Execution time	Memory
139038		hamzqq9	Roller Coaster Railroad (IOI16_railroad)	C++14	30 / 100	1038 ms	34300 KiB

railroad

#include "railroad.h"
#include<bits/stdc++.h>
#define st first
#define nd second
#define pb push_back
#define pf push_front
#define ppb pop_back
#define ppf pop_front
#define umax(x,y) x=max(x,y)
#define umin(x,y) x=min(x,y)
#define ll long long
#define ii pair<int,int>
#define iii pair<int,ii>
#define iiii pair<ii,ii>
#define sz(x) ((int) x.size())
#define orta ((bas+son)/2)
#define all(x) x.begin(),x.end()
#define inf 1000000000
#define MOD 1000000007 
#define N 400005
#define LOG 20
#define KOK 300
#define EPS 0.0000001
using namespace std;

int n,cnt;
vector<int> pre,dad;
int tut[N];

struct edge {

	int a,b,c;

};

int find(int x) {return dad[x]=(x==dad[x]?x:find(dad[x]));}

void merge(int x,int y) {

	dad[find(x)]=find(y);

}

long long plan_roller_coaster(std::vector<int> s, std::vector<int> t) {

	map<int,int> mp;

	n=sz(s);

	for(int i=0;i<n;i++) {

		mp[s[i]]=1;
		mp[t[i]]=1;

	}

	mp[inf]=1;

	for(auto& x:mp) {

		x.nd=++cnt;
		tut[cnt]=x.st;

	}

	dad=pre=vector<int>(cnt+5,0);

	for(int i=1;i<=cnt;i++) dad[i]=i;

	for(int i=0;i<n;i++) {

//		cerr<<s[i]<<" "<< t[i]<<"\n";

		s[i]=mp[s[i]];
		t[i]=mp[t[i]];

		merge(s[i],t[i]);

	//	cerr<< "to : \n";

//		cerr<<s[i] <<" "<<t[i]<<"\n";

//		cerr<<"-------------------\n";

		if(s[i]<=t[i]) {

			pre[s[i]]++;
			pre[t[i]]--;

		}
		else {

			pre[t[i]]--;
			pre[s[i]]++;

		}

	}

	ll ans=0;

	vector<edge> q;

	for(int i=1;i<cnt;i++) { 

		pre[i]+=pre[i-1];

//		cerr<<i << " " << pre[i] <<"\n";

		if(pre[i]>1) {

			ans+=pre[i]-1;

		}

		if(pre[i]!=1) merge(i,i+1);

		if(find(i)!=find(i+1)) q.pb({i,i+1,tut[i+1]-tut[i]});

	}

	sort(all(q),[](edge x,edge y) {

		return x.c<y.c;

	});

	for(auto x:q) {

		if(find(x.a)!=find(x.b)) {

			merge(x.a,x.b);

			ans+=x.c;

		}

	}

	return ans;

}

• Subtask 1: 0 / 11
• Subtask 2: 0 / 23
• Subtask 3: 30 / 30
• Subtask 4: 0 / 36