Submission #1078090

#	Time	Username	Problem	Language	Result	Execution time	Memory
1078090		noyancanturk	Simurgh (IOI17_simurgh)	C++17	0 / 100	1 ms	348 KiB

simurgh

#include "simurgh.h"

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

#define pb push_back

const int lim=510;

int n;
int v[lim][lim];
int edgecnt[lim],p[lim];

struct{
	int par[lim];
	void init(){
		for(int i=0;i<n;i++)par[i]=i;
	}
	int find(int i){
		if(i==par[i])return i;
		return par[i]=find(par[i]);
	}
	void unite(int i,int j){
		i=find(i),j=find(j);
		par[i]=j;
	}
}dsu;

void findedgecnt(int node){
	vector<int>r;
	for(int i=0;i<n;i++){
		if(i==node)continue;
		r.pb(v[node][i]);
	}
	edgecnt[node]=count_common_roads(r);
	if(node)edgecnt[node]--;
}

int lineadd(int node){
	vector<int>r;
	for(int i=1;i+1<n;i++){
		r.pb(v[i][i+1]);
	}
	r.pb(v[0][node]);
	return count_common_roads(r);
}

vector<int>legit;

vector<int> find_roads(int N, vector<int> u1, vector<int> u2) {
	n=N;
	legit.clear();
	for(int i=0;i<n;i++)p[i]=-1;
	for(int i=0;i<n;i++)
		for(int j=0;j<n;j++)
			v[i][j]=-1;
	int m=u1.size();
	for(int i=0;i<m;i++){
		v[u1[i]][u2[i]]=i;
		v[u2[i]][u1[i]]=i;
	}
	if(m==n*(n-1)/2){
		for(int i=0;i<n;i++)findedgecnt(i);
		int best=lineadd(1);
		vector<int>toad;
		toad.pb(1);
		for(int i=2;i<n;i++){
			int cnt=lineadd(i);
			if(cnt==best){
				toad.pb(i);
			}else if(best<cnt){
				best=cnt;
				toad.clear();
				toad.pb(i);
			}
		}
		vector<int>q;
		for(int i:toad){
			q.pb(i);
			p[i]=0;
			legit.pb(v[0][i]);
		}
		while(q.size()){
			int node=q.back();
			q.pop_back();
			vector<int>dudes;
			for(int i=1;i<n;i++){
				if(p[i]==-1)dudes.pb(i);
			}
			int tt=-1;
			vector<int>found;
			while(edgecnt[node]){
				int l=tt+2,r=dudes.size()-1,ans=tt+1;
				while(l<=r){
					int mid=(l+r)>>1;
					vector<int>wow=legit;
					for(int i=0;i<mid;i++){
						wow.pb(v[0][dudes[i]]);
					}
					for(int i=mid;i<dudes.size();i++){
						wow.pb(v[node][dudes[i]]);
					}
					int cnt=count_common_roads(wow);
					if(cnt==edgecnt[node]){
						ans=mid;
						l=mid+1;
					}else{
						r=mid-1;
					}
				}
				found.pb(dudes[ans]);
				edgecnt[node]--;
				tt=ans;
			}
			for(int i:found){
				p[i]=node;
				legit.pb(v[node][i]);
				q.pb(i);
			}
		}
		/*
		cerr<<"found :: ";
		for(int i:legit)cerr<<i<<" ";
		cerr<<"\n";
		*/
		return legit;
	}
	return legit;
	/*
	vector<int> r(n - 1);
	for(int i = 0; i < n - 1; i++)
		r[i] = i;
	int common = count_common_roads(r);
	if(common == n - 1)
		return r;
	r[0] = n - 1;
	return r;
	*/
}

Compilation message (stderr)

simurgh.cpp: In function 'std::vector<int> find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:100:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  100 |      for(int i=mid;i<dudes.size();i++){
      |                    ~^~~~~~~~~~~~~
simurgh.cpp: At global scope:
simurgh.cpp:27:2: warning: 'dsu' defined but not used [-Wunused-variable]
   27 | }dsu;
      |  ^~~

• Subtask 1: 0 / 13
• Subtask 2: 0 / 17
• Subtask 3: 0 / 21
• Subtask 4: 0 / 19
• Subtask 5: 0 / 30