Submission #912669

#	Time	Username	Problem	Language	Result	Execution time	Memory
912669		Wansur	Split the Attractions (IOI19_split)	C++14	100 / 100	204 ms	43860 KiB

split

#include <bits/stdc++.h>
#define f first
#define s second
#define ent '\n'

using namespace std;
typedef long long ll;
const int mx=2e5+12;

pair<int,int> fup[mx];
vector<int> g[mx];
set<int> e[mx];
int Ans[mx];
int par[mx];
int tin[mx];
int ver[mx];
int sz[mx];
int pos[]={1,2,3};
int timer;

void calc(int v){
	sz[v]=1;
	for(int to:g[v]){
		if(sz[to]>0)continue;
		calc(to);
		par[to]=v;
		e[v].insert(to);
		e[to].insert(v);
		sz[v]+=sz[to];
	}
}

void dfs(int v,int p){
	tin[v]=fup[v].f=++timer;
	fup[v].s=v;
	ver[tin[v]]=v;
	for(int to:g[v]){
		if(to==p)continue;
		if(tin[to]>0){
			fup[v]=min(fup[v],{tin[to],v});
		}
		else{
			dfs(to,v);
			fup[v]=min(fup[v],fup[to]);
		}
	}
}

void get(int v,int p,int &cnt,int t){
	if(!cnt)return;
	Ans[v]=pos[t];
	cnt--;
	if(!cnt)return;
	for(int to:e[v]){
		if(to!=p)get(to,v,cnt,t);
	}
}

std::vector<int> find_split(int n, int a, int b, int c, std::vector<int> p, std::vector<int> q){
	for(int i=0;i<p.size();i++){
		g[p[i]].push_back(q[i]);
		g[q[i]].push_back(p[i]);
	}
	if(a>b){
		swap(a,b);
		swap(pos[0],pos[1]);
	}
	if(a>c){
		swap(a,c);
		swap(pos[0],pos[2]);
	}
	if(b>c){
		swap(b,c);
		swap(pos[1],pos[2]);
	}
	int A=a,B=b,C=c;
	calc(0);
	dfs(0,0);
	int v=-1;
	for(int i=0;i<n;i++){
	}
	for(int i=1;i<n;i++){
		if(sz[i]<a)continue;
		bool ok=1;
		for(int to:e[i]){
			if(sz[to]>=a && tin[to]>tin[i])ok=0;
		}
		if(ok){
			v=i;
			break;
		}
	}
	vector<int> ans(n);
	if(v<0)return ans;
	bool bad=0;
	vector<int> edg;
	for(int to:e[v]){
		if(tin[to]>tin[v])edg.push_back(to);
	}
	for(int to:edg){
		if(sz[v]-sz[to]<a){
			break;
		}
		if(fup[to].f<tin[v]){
			sz[v]-=sz[to];
			e[v].erase(to);
			e[to].erase(v);
			e[ver[fup[to].f]].insert(fup[to].s);
			e[fup[to].s].insert(ver[fup[to].f]);
		}
	}
	e[par[v]].erase(v);
	e[v].erase(par[v]);
	if(sz[v]>=a && n-sz[v]>=b){
		get(v,0,a,0);
		get(0,0,b,1);
		for(int i=0;i<n;i++){
			ans[i]=Ans[i];
			if(!ans[i])ans[i]=pos[2];
		}
	}
	else if(sz[v]>=b && n-sz[v]>=a){
		get(v,0,b,1);
		get(0,0,a,0);
		for(int i=0;i<n;i++){
			ans[i]=Ans[i];
			if(!ans[i])ans[i]=pos[2];
		}
	}
	return ans;
}

Compilation message (stderr)

split.cpp: In function 'std::vector<int> find_split(int, int, int, int, std::vector<int>, std::vector<int>)':
split.cpp:60:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   60 |  for(int i=0;i<p.size();i++){
      |              ~^~~~~~~~~
split.cpp:76:6: warning: unused variable 'A' [-Wunused-variable]
   76 |  int A=a,B=b,C=c;
      |      ^
split.cpp:76:10: warning: unused variable 'B' [-Wunused-variable]
   76 |  int A=a,B=b,C=c;
      |          ^
split.cpp:76:14: warning: unused variable 'C' [-Wunused-variable]
   76 |  int A=a,B=b,C=c;
      |              ^
split.cpp:95:7: warning: unused variable 'bad' [-Wunused-variable]
   95 |  bool bad=0;
      |       ^~~

• Subtask 1: 7 / 7
• Subtask 2: 11 / 11
• Subtask 3: 22 / 22
• Subtask 4: 24 / 24
• Subtask 5: 36 / 36