Submission #276939

#	Time	Username	Problem	Language	Result	Execution time	Memory
276939		eohomegrownapps	Roller Coaster Railroad (IOI16_railroad)	C++14	0 / 100	869 ms	23800 KiB

railroad

#include "railroad.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

long long plan_roller_coaster(std::vector<int> s, std::vector<int> t) {
    int n = (int) s.size();
    set<pair<int,int>> lrset;
    set<pair<int,int>> rlset;
    for (int i = 0; i<n; i++){
    	lrset.insert({s[i],t[i]});
    	rlset.insert({t[i],s[i]});
    }
    while (lrset.size()>1){
    	/*cout<<'\n';
    	for (auto p : lrset){
    		cout<<p.first<<' '<<p.second<<'\n';
    	}*/
    	auto el = lrset.begin();
    	int firstl = el->first;
    	auto smallestrpair = rlset.lower_bound({firstl+1,-1});
    	if (smallestrpair!=rlset.begin()&&*prev(smallestrpair,1)==make_pair(el->second,el->first)){
    		smallestrpair = rlset.lower_bound({el->second,el->first-1});
    	}
    	if (smallestrpair==rlset.begin()){
    		el = next(el,1);
    		firstl = el->first;
    		smallestrpair = rlset.lower_bound({firstl+1,-1});
	    	if (smallestrpair!=rlset.begin()&&*prev(smallestrpair,1)==make_pair(el->second,el->first)){
	    		smallestrpair = rlset.lower_bound({el->second,el->first-1});
	    	}
	    	if (smallestrpair==rlset.begin()){
    			return 1;
    		}
    	}
    	smallestrpair = prev(smallestrpair,1);
    	//merge el with smallestrpair
    	int fpairl = el->first;
    	int fpairr = el->second;
    	int spairl = smallestrpair->second;
    	int spairr = smallestrpair->first;
    	lrset.erase({fpairl,fpairr});
    	rlset.erase({fpairr,fpairl});
    	lrset.erase({spairl,spairr});
    	rlset.erase({spairr,spairl});
    	lrset.insert({spairl,fpairr});
    	rlset.insert({fpairr,spairl});
    }
    return 0;
}

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