Submission #71302

#	Time	Username	Problem	Language	Result	Execution time	Memory
71302		Kmcode	Simurgh (IOI17_simurgh)	C++14	51 / 100	180 ms	20456 KiB

simurgh

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

//#include "simurgh.h"
int count_common_roads(const std::vector<int>& r);

#define MAX 512*512
struct UF{
	int belong[MAX];
	int sz[MAX];
	int col[MAX];
	UF(){
		memset(belong,-1,sizeof(belong));
		for(int i=0;i<MAX;i++)sz[i]=1;
	}
	inline int root(int b){
		if(belong[b]==-1){
			return b;
		}
		return belong[b]=root(belong[b]);
	}
	void merge(int a,int b){
		a=root(a);
		b=root(b);
		if(a==b)return;
		if(a>b)swap(a,b);
		belong[a]=b;
		sz[b]+=sz[a];
	}
};
namespace solver{
	const int white=MAX-3;
	const int black=MAX-2;
	vector<pair<int,int> > v;
	vector<pair<int,int> > g[MAX];
	int id[MAX];
	int pr[MAX];
	int dep[MAX];
	UF uf;
	vector<int> road;
	vector<int> swa;
	
	inline void dfs(int b,int pr2=-1,int d=0){
		dep[b]=d;
			for(auto go:g[b]){
				if(go.first==pr2)continue;
				dfs(go.first,b,d+1);
				pr[go.first]=b;
				id[go.first]=go.second;
			}
	}
	int ini;
	int cn;
	int ask(){
		cn++;
		assert(cn<=30000);
		return count_common_roads(road);
	}
	void make_tree(){
		UF uf2;
		for(int i=0;i<v.size();i++){
			swa.push_back(-1);
			if(uf2.root(v[i].first)!=uf2.root(v[i].second)){
				uf2.merge(v[i].first,v[i].second);
				g[v[i].first].push_back(make_pair(v[i].second,i) );
				g[v[i].second].push_back(make_pair(v[i].first,i) );
				road.push_back(i);
				swa[i]=road.size()-1;
			}
		}
		ini=ask();
	}
	int query(int exp,int add){
		road[swa[exp]]=add;
		int z=ask();
		road[swa[exp]]=exp;
		return z-ini;
	}
	inline void check(int tree1,int tree2){
		int r1=uf.root(tree1);
		int r2=uf.root(tree2);
		if(r1==r2)return;
		if(r1==black||r1==white){
			if(r2==black||r2==white){
				return;
			}
		}
		int ret=query(tree1,tree2);
		if(ret==0){
			uf.merge(tree1,tree2);
			return;
		}
		if(ret>0){
			uf.merge(black,tree2);
			uf.merge(white,tree1);
			return;
		}
		uf.merge(black,tree1);
		uf.merge(white,tree2);
	}
	vector<int> mer[MAX];
	std::vector<int> find_roads(int n, std::vector<int> u1, std::vector<int> v1) {
		for(int i=0;i<u1.size();i++){
			v.push_back(make_pair(u1[i],v1[i]));
		}
		make_tree();
		if(ini==n-1){
			return road;
		}
		if(ini==0){
			for(int i=0;i<road.size();i++){
				uf.merge(road[i],white);
			}
		}
		dfs(0);
		for(int i=0;i<v.size();i++){
			if(dep[v[i].first]>dep[v[i].second])swap(v[i].first,v[i].second);
			if(pr[v[i].second]==v[i].first)continue;
			int a=v[i].first;
			int b=v[i].second;
			while(a!=b){
				if(dep[a]<dep[b]){
					check(id[b],i);
					b=pr[b];
				}
				else{
					check(id[a],i);
					a=pr[a];
				}
			}
		}
		vector<int> ans;
		UF uf2;
		for(int i=0;i<v.size();i++){
			if(uf.root(i)==black){
				ans.push_back(i);
				uf2.merge(v[i].first,v[i].second);
			}
		}
		for(int i=0;i<v.size();i++){
			mer[uf.root(i)].push_back(i);
		}
		for(int i=0;i<v.size();i++){
			if(i==white||i==black)continue;
			//mergeable
			if(mer[i].size()==0)continue;
			UF uf3;
			bool ok=false;
			for(int el:mer[i]){
				int a=v[el].first;
				int b=v[el].second;
				if(uf3.root(a)==uf3.root(b)){
					ok=true;
					break;
				}
				uf3.merge(a,b);
				if(uf2.root(a)==uf2.root(b)){
					ok=true;
					break;
				}
			}
			if(ok==false){
				for(int el:mer[i]){
					road.push_back(el);
					int a=v[el].first;
					int b=v[el].second;
					//uf2.merge(a,b);
				}
			}
		}
		assert(ans.size()>=n-1);
		return ans;
	}
	
}


std::vector<int> find_roads(int n, std::vector<int> u, std::vector<int> v) {
	return solver::find_roads(n,u,v);
}

Compilation message (stderr)

simurgh.cpp: In function 'void solver::make_tree()':
simurgh.cpp:62:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<v.size();i++){
               ~^~~~~~~~~
simurgh.cpp: In function 'std::vector<int> solver::find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:104:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<u1.size();i++){
               ~^~~~~~~~~~
simurgh.cpp:112:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int i=0;i<road.size();i++){
                ~^~~~~~~~~~~~
simurgh.cpp:117:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<v.size();i++){
               ~^~~~~~~~~
simurgh.cpp:135:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<v.size();i++){
               ~^~~~~~~~~
simurgh.cpp:141:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<v.size();i++){
               ~^~~~~~~~~
simurgh.cpp:144:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<v.size();i++){
               ~^~~~~~~~~
simurgh.cpp:166:10: warning: unused variable 'a' [-Wunused-variable]
      int a=v[el].first;
          ^
simurgh.cpp:167:10: warning: unused variable 'b' [-Wunused-variable]
      int b=v[el].second;
          ^
In file included from /usr/include/c++/7/cassert:44:0,
                 from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:33,
                 from simurgh.cpp:1:
simurgh.cpp:172:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   assert(ans.size()>=n-1);
          ~~~~~~~~~~^~~~~

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