oj.uz

답안 #68819

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
68819 2018-08-18T16:09:12 Z imsifile 갈라파고스 여행 (FXCUP3_island) C++
42 / 100
 3000 ms 170496 KB 
#include<stdio.h>
#include<algorithm>
#include<vector>
#include<queue>
#include<set>
using namespace std;

int N, in, iix, lcn[303030], deg[303030];
vector<int> leaf[303030], tree[303030], ins;
vector<int> con[303030], inv[303030];

void edge(vector<int> *v, int s, int e){ v[s].push_back(e), v[e].push_back(s); }

void divide(){
	for(int i=1; i<=N; i++){
		if(deg[i] > N-1-deg[i]) iix=i;
		if(deg[i] > 1){
			in++, ins.push_back(i);
			for(int j=con[i].size(); j--;){
				int e=con[i][j];
				if(deg[e]==1) leaf[i].push_back(e), lcn[i]++;
				else tree[i].push_back(e);
			}
		}
		con[i].clear();
	}
}

int tmp[303030], dap;
vector<int> bw[2];
void eachin(int s, int e) { edge(inv, s, e), deg[s]--, deg[e]--, dap++; }

void dfs1(int s, int ix, int col){
	tmp[ix]=1;
	if(ix!=s) bw[col].push_back(ix);
	for(int i=tree[ix].size(); i--;){
		int e=tree[ix][i];
		if(!tmp[e]) dfs1(s, e, col^1);
	}
}

void color_tree(int s){
	if(s == -1){
		dfs1(-1, ins[0], 0);
		if(bw[0].size() <= 2){
			int sz = bw[0].size();
			for(int i=0; i<sz-1; i++) eachin(bw[0][i], bw[0][i+1]);
			sz = bw[1].size();
			for(int i=0; i<sz; i++) eachin(bw[1][i], bw[1][(i+1)%sz]);
		}
		else{
			int sz = bw[1].size();
			for(int i=0; i<sz-1; i++) eachin(bw[1][i], bw[1][i+1]);
			sz = bw[0].size();
			for(int i=0; i<sz; i++) eachin(bw[0][i], bw[0][(i+1)%sz]);
		}
		return;
	}

	int left=in-1;
	for(int i=tree[s].size(); i--;) tmp[tree[s][i]] = 1;
	for(int i=0; i<in; i++){
		int e=ins[i];
		if(tmp[e]==0 && s!=e) eachin(s, e), left--;
		tmp[e]=0;
	}
	if(left >= 3){
		int sz=tree[s].size();
		for(int i=0; i<sz; i++){
			int a=tree[s][i], b=tree[s][(i+1)%sz];
			eachin(a, b);
		}
		return;
	}
	dfs1(s, s, 1);
	if(left == 1){
		if(bw[0].size() >= 2) eachin(bw[0][0], bw[0][1]);
		else eachin(bw[1][0], bw[1][1]);
	}
	else{
		eachin(bw[0][0], bw[0][1]);
		if(bw[0].size() >= 3) eachin(bw[0][0], bw[0][2]);
		else eachin(bw[1][0], bw[1][1]);
	}
}

vector<int> lin;
void dfs2(int ix){
	tmp[ix]=1;
	lin.push_back(ix);
	for(int i=tree[ix].size(); i--;){
		int e=tree[ix][i];
		if(!tmp[e]) dfs2(e);
	}
}

void line_tree(int s){
	dfs2(s);
	int sz=lin.size();
	eachin(lin[0], lin[sz-1]);
	for(int i=0; i<sz-2; i+=2) eachin(lin[i], lin[i+2]);
	for(int i=1; i<sz-2; i+=2) eachin(lin[i], lin[i+2]);
}

struct my {
	int sum, ix;
	my(int sum_=0, int ix_=0){ sum=sum_, ix=ix_; }
	bool operator< (const my &c) const {
		return sum < c.sum;
	}
};

priority_queue<my> ld, l0, d0;
void push(int s){
	my m(lcn[s]+deg[s], s);
	if(lcn[s]>0 && deg[s]>0) ld.push(m);
	if(lcn[s]==0 && deg[s]>0) l0.push(m);
	if(lcn[s]>0 && deg[s]==0) d0.push(m);
}
void eachmatch(int d, int l){
	deg[d]--, lcn[l]--;
	edge(inv, d, leaf[l][lcn[l]]); dap++;
}

void match(){
	for(int i=0; i<in; i++) push(ins[i]);
	while(!ld.empty()){
		my s=ld.top(), e;
		ld.pop();
		if(!ld.empty()) e=ld.top(), ld.pop();
		else if(!d0.empty()) e=d0.top(), d0.pop();
		else e=l0.top(), l0.pop(), swap(s, e);
		eachmatch(s.ix, e.ix);
		push(s.ix); push(e.ix);
	}
	while(!l0.empty()){
		my s=l0.top(); l0.pop();
		my e=d0.top(); d0.pop();
		eachmatch(s.ix, e.ix);
		push(s.ix); push(e.ix);
	}
}

void debug(){
	puts("Inner Nodes");
	for(int i=0; i<in; i++){
		int s=ins[i];
		printf("%d: ", s);
		for(int j=leaf[s].size(); j--;) printf("%d ", leaf[s][j]);
		puts("");
	}
	puts("Edge");
	for(int i=1; i<=N; i++){
		for(int j=con[i].size(); j--;) if(i<con[i][j]) printf("%d-%d\n", i, con[i][j]);
	}
	puts("Anti-Edge");
	for(int i=1; i<=N; i++){
		for(int j=inv[i].size(); j--;) if(i<inv[i][j]) printf("%d-%d\n", i, inv[i][j]);
	}
}

int cjs[303030], ijs[303030];
set<pair<int,int> > sets;
void get_euler(int s, int typ){
	if(typ){
		while(cjs[s] < con[s].size()){
			int e=con[s][cjs[s]++];
			if(sets.find(make_pair(s,e)) != sets.end()) continue;
			sets.insert(make_pair(s,e)), sets.insert(make_pair(e,s));
			get_euler(e, typ^1);
		}
	}
	else{
		while(ijs[s] < inv[s].size()){
			int e=inv[s][ijs[s]++];
			if(sets.find(make_pair(s,e)) != sets.end()) continue;
			sets.insert(make_pair(s,e)), sets.insert(make_pair(e,s));
			get_euler(e, typ^1);
		}
	}
	printf("%d ", s);
}

int main(){
//	freopen("Subtask 1/11.in","r",stdin);
	scanf("%d", &N);
	for(int i=0; i<N-1; i++){
		int s, e;
		scanf("%d%d", &s, &e);
		edge(con, s, e);
		deg[s]++, deg[e]++;
	}
	divide();
	if(in <= 1){ puts("0"); return 0; }
	if(in == 2){
		int a=ins[0], b=ins[1];
		int mi = min(lcn[a],lcn[b]);
		lcn[a]=lcn[b]=deg[a]=deg[b]=mi;
		sort(leaf[a].begin(), leaf[a].end());
		sort(leaf[b].begin(), leaf[b].end());
		for(int i=0; i<mi; i++){
			edge(con, a, leaf[a][i]);
			edge(con, b, leaf[b][i]);
		}
	}
	else if(in == 3){
		if(iix){
			int oth = N-1-deg[iix];
			sort(leaf[iix].begin(), leaf[iix].end());
			lcn[iix]=oth+1-tree[iix].size(), deg[iix]=oth+1;
		}
		int a=-1, b=-1, c=-1;
		iix = ins[0];
		for(int i=0; i<3; i++){
			if(deg[iix] < deg[ins[i]]) iix=ins[i];
			if(tree[ins[i]].size() == 2) b=ins[i];
			else if(a<0) a=ins[i];
			else c=ins[i];
		}
		for(int j=0; j<lcn[a]; j++) edge(con, a, leaf[a][j]);
		for(int j=0; j<lcn[b]; j++) edge(con, b, leaf[b][j]);
		for(int j=0; j<lcn[c]; j++) edge(con, c, leaf[c][j]);

		eachin(a, c);
		if(iix==a || iix==b){
			deg[a]--, deg[b]--;
			edge(con, b, c);
		}
		if(iix==c){
			deg[c]--, deg[b]--;
			edge(con, b, a);
		}
	}
	else{
		if(iix){
			int oth = N-1-deg[iix];
			sort(leaf[iix].begin(), leaf[iix].end());
			lcn[iix]=oth-tree[iix].size(), deg[iix]=oth;
		}
		for(int i=0; i<in; i++){
			int s=ins[i];
			for(int j=0; j<lcn[s]; j++) edge(con, s, leaf[s][j]);
			for(int j=tree[s].size(); j--;) con[s].push_back(tree[s][j]);
		}
		if(in == 4){
			for(int i=0; i<in; i++){
				int s=ins[i];
				for(int j=tree[s].size(); j--;) tmp[tree[s][j]] = 1;
				for(int j=i+1; j<in; j++){
					if(tmp[ins[j]]==0) eachin(s, ins[j]);
				}
				for(int j=tree[s].size(); j--;) tmp[tree[s][j]] = 0;
			}
		}
		else{
			int lsum=0, ovc=0, ovi;
			for(int i=0; i<in; i++) lsum += lcn[ins[i]];
			for(int i=0; i<in; i++){
				int s=ins[i];
				if(deg[s]+lcn[s] > lsum) ovc++, ovi=s;
			}
			if(ovc==0) color_tree(-1);
			else if(ovc==1) color_tree(ovi);
			else line_tree(ovi);
		}
	}
	match();
//	debug();
	printf("%d\n", dap*2);
	get_euler(ins[0], 1);
	return 0;
}

Compilation message

island.cpp: In function 'void get_euler(int, int)':
island.cpp:166:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   while(cjs[s] < con[s].size()){
         ~~~~~~~^~~~~~~~~~~~~~~
island.cpp:174:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   while(ijs[s] < inv[s].size()){
         ~~~~~~~^~~~~~~~~~~~~~~
island.cpp: In function 'int main()':
island.cpp:186:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &N);
  ~~~~~^~~~~~~~~~
island.cpp:189:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &s, &e);
   ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
42.0 / 42.0

# 결과 실행 시간 메모리 Grader output
1 Correct 32 ms 28792 KB Correct
2 Correct 31 ms 29072 KB Correct
3 Correct 30 ms 29072 KB Correct
4 Correct 36 ms 29244 KB Correct
5 Correct 33 ms 29244 KB Correct
6 Correct 34 ms 29244 KB Correct
7 Correct 34 ms 29244 KB Correct
8 Correct 32 ms 29244 KB Correct
9 Correct 35 ms 29244 KB Correct
10 Correct 34 ms 29244 KB Correct
11 Correct 35 ms 29244 KB Correct
12 Correct 33 ms 29244 KB Correct
13 Correct 31 ms 29560 KB Correct
14 Correct 29 ms 29560 KB Correct
15 Correct 34 ms 29560 KB Correct
16 Correct 32 ms 29560 KB Correct
17 Correct 30 ms 29560 KB Correct
18 Correct 33 ms 29560 KB Correct
19 Correct 29 ms 29560 KB Correct
20 Correct 27 ms 29560 KB Correct

Subtask #2
0 / 58.0

# 결과 실행 시간 메모리 Grader output
1 Correct 32 ms 28792 KB Correct
2 Correct 31 ms 29072 KB Correct
3 Correct 30 ms 29072 KB Correct
4 Correct 36 ms 29244 KB Correct
5 Correct 33 ms 29244 KB Correct
6 Correct 34 ms 29244 KB Correct
7 Correct 34 ms 29244 KB Correct
8 Correct 32 ms 29244 KB Correct
9 Correct 35 ms 29244 KB Correct
10 Correct 34 ms 29244 KB Correct
11 Correct 35 ms 29244 KB Correct
12 Correct 33 ms 29244 KB Correct
13 Correct 31 ms 29560 KB Correct
14 Correct 29 ms 29560 KB Correct
15 Correct 34 ms 29560 KB Correct
16 Correct 32 ms 29560 KB Correct
17 Correct 30 ms 29560 KB Correct
18 Correct 33 ms 29560 KB Correct
19 Correct 29 ms 29560 KB Correct
20 Correct 27 ms 29560 KB Correct
21 Correct 272 ms 43900 KB Correct
22 Correct 1070 ms 160808 KB Correct
23 Correct 684 ms 160808 KB Correct
24 Correct 804 ms 160808 KB Correct
25 Correct 2291 ms 161412 KB Correct
26 Correct 1063 ms 161412 KB Correct
27 Correct 355 ms 161412 KB Correct
28 Correct 303 ms 161412 KB Correct
29 Correct 2047 ms 161412 KB Correct
30 Execution timed out 3028 ms 170496 KB Time limit exceeded
31 Halted 0 ms 0 KB -