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답안 #60966

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
60966 2018-07-25T04:33:37 Z spencercompton Min-max tree (BOI18_minmaxtree) C++14
58 / 100
 1000 ms 52644 KB 
#include <bits/stdc++.h>
using namespace std;
class Edge{
public:
	int to, rev;
	bool cap;
	Edge(int a, bool b, int c){
		to = a;
		cap = b;
		rev = c;
	}
};
class Flow{
public:
	int n = 140010;
	vector<Edge> adj[140010];
	int sz[140010];
	int dist[140010];
	int nxt[140010];
	bool v[140010];
	int li[140010];
	int point;
	Flow(){
		for(int i = 0; i<n; i++){
			dist[i] = -1;
		}
	}
	void add(int i, int j){

		adj[i].push_back(Edge(j,1,sz[j]++));
		adj[j].push_back(Edge(i,0,sz[i]++));
	}
	bool dfs(int now){
		if(now==1){
			return true;
		}
		for(; nxt[now]<sz[now]; nxt[now]++){
			int i = nxt[now];
			int to = adj[now][i].to;
			if(adj[now][i].cap && dist[to] == dist[now]+1 && dfs(to)){
				adj[now][i].cap = false;
				adj[to][adj[now][i].rev].cap = true;
				return true;
			}
		}
		return false;
	}
	int bfs(){
		dist[0] = 0;
		point = 1;
		v[0] = false;
		nxt[0] = 0;
		for(int i = 0; i<point; i++){
			int now = li[i];
			for(int j = 0; j<sz[now]; j++){
				int to = adj[now][j].to;
				if(dist[to]==-1 && adj[now][j].cap>0){
					dist[to] = dist[now]+1;
					li[point++] = to;
					nxt[to] = 0;
					if(to==1){
						return 1;
					}
				}
			}
		}
		return 0;
	}
	int flow(){
		int ans = 0;
		while(bfs()>0){
			//do nothing
			for(int i = 0; i<sz[0]; i++){
				int to = adj[0][i].to;
				if(dist[to]==1 && adj[0][i].cap && dfs(to)){
					adj[0][i].cap = false;
					adj[to][adj[0][i].rev].cap = true;
				}
			}
			for(int i = 0; i<point; i++){
				dist[li[i]] = -1;
			}
		}
		return ans;
	}
};
int maxi[70000];
int mini[70000];
int lc[18][70000];
vector<int> adj[70000];
set<int> maxs[70000];
set<int> mins[70000];
vector<int> remmax[70000];
vector<int> remmin[70000];
int h[70000];
int dfs1(int now, int from, int x){
	lc[0][now] = from;
	h[now] = x;
	for(int i = 0; i<adj[now].size(); i++){
		int to = adj[now][i];
		if(to==from){
			continue;
		}
		dfs1(to,now,x+1);
	}
}
int mgmin(int a, int b){
	if(mins[a].size()>mins[b].size()){
		swap(a,b);
	}
	for(auto it = mins[a].begin(); it!=mins[a].end(); it++){
		mins[b].insert(*it);
	}
	mins[a].clear();
	return b;
}
int mgmax(int a, int b){
	if(maxs[a].size()>maxs[b].size()){
		swap(a,b);
	}
	for(auto it = maxs[a].begin(); it!=maxs[a].end(); it++){
		maxs[b].insert(*it);
	}
	maxs[a].clear();
	return b;
}
int lca(int a, int b){
	if(a==b){
		return a;
	}
	if(h[a] < h[b]){
		swap(a,b);
	}
	for(int i = 17; i>=0; i--){
		if(lc[i][a]!=-1 && h[lc[i][a]]>=h[b]){
			a = lc[i][a];
		}
	}
	if(a==b){
		return a;
	}
	for(int i = 17; i>=0; i--){
		int toa = lc[i][a];
		int tob = lc[i][b];
		if(toa!=tob){
			a = toa;
			b = tob;
		}
	}
	return lc[0][a];
}
pair<int, int> go(int now, int from){
	//returns minid, maxid
	pair<int, int> ret = make_pair(now,now);
	for(int i = 0; i<adj[now].size(); i++){
		int to = adj[now][i];
		if(to==from){
			continue;
		}
		pair<int, int> got = go(to,now);
		ret.first = mgmin(ret.first,got.first);
		ret.second = mgmax(ret.second,got.second);
	}
	for(int i = 0; i<remmax[now].size(); i++){
		maxs[ret.second].erase(maxs[ret.second].find(remmax[now][i]));
	}
	for(int i = 0; i<remmin[now].size(); i++){
		mins[ret.first].erase(mins[ret.first].find(remmin[now][i]));
	}
	if(maxs[ret.second].size()>0){
		maxi[now] = *maxs[ret.second].begin();
	}
	else{
		maxi[now] = -1;
	}
	if(mins[ret.first].size()>0){
		mini[now] = *mins[ret.first].rbegin();
	}
	else{
		mini[now] = -1;
	}
	return ret;
}
int main(){
	// cout << "MAIN " << endl;
	// Flow f = Flow();
	// cout << "X " << endl;
	// f.add(0,1);
	// f.add(0,4);
	// f.add(0,69);
	// f.add(69,42);
	// f.add(42,13);
	// f.add(42,1);
	// cout << "Y " << endl;
	// cout << f.flow() << endl;
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	int n;
	cin >> n;
	for(int i = 1; i<n; i++){
		int a, b;
		cin >> a >> b;
		a--;
		b--;
		adj[a].push_back(b);
		adj[b].push_back(a);
	}
	dfs1(0,-1,0);
	for(int i = 1; i<18; i++){
		for(int j = 0; j<n; j++){
			if(lc[i-1][j]==-1){
				lc[i][j] = -1;
			}
			else{
				lc[i][j] = lc[i-1][lc[i-1][j]];
			}
		}
	}
	int q;
	cin >> q;
	for(int i = 0; i<q; i++){
		string s;
		int a, b, v;
		cin >> s >> a >> b >> v;
		a--;
		b--;
		int l = lca(a,b);
		if(s=="M"){
			//maxi
			maxs[a].insert(v);
			maxs[b].insert(v);
			remmax[l].push_back(v);
		}
		else{
			mins[a].insert(v);
			mins[b].insert(v);
			remmin[l].push_back(v);
		}
	}
	go(0,-1);
	map<int, int> m;
	map<int, int> rev;
	int point = 2+n;
	Flow f = Flow();
	for(int i = 1; i<n; i++){
		if(mini[i]!=-1 && m.find(mini[i])==m.end()){
			rev[point] = mini[i];
			f.add(point,1);
			m[mini[i]] = point++;
		}
		if(maxi[i]!=-1 && m.find(maxi[i])==m.end()){
			rev[point] = maxi[i];
			f.add(point,1);
			m[maxi[i]] = point++;
		}
	}
	for(int i = 1; i<n; i++){
		f.add(0,2+i);
		if(mini[i]!=-1){
			f.add(2+i,m[mini[i]]);
		}
		if(maxi[i]!=-1){
			f.add(2+i,m[maxi[i]]);
		}
	}
	f.flow();
	for(int i = 1; i<n; i++){
		int found = -1;
		for(int j = 0; j<f.adj[2+i].size(); j++){
			int to = f.adj[2+i][j].to;
			if(to!=0 && f.adj[2+i][j].cap==0){
				found = rev[to];
			}
		}
		
		if(found!=-1){
			cout << (i+1) << " " << (lc[0][i]+1) << " " << found << "\n";
		}
		else if(maxi[i]!=-1){
			cout << (i+1) << " " << (lc[0][i]+1) << " " << maxi[i] << "\n";
		}
		else if(mini[i]!=-1){
			cout << (i+1) << " " << (lc[0][i]+1) << " " << mini[i] << "\n";
		}
		else{
			cout << (i+1) << " " << (lc[0][i]+1) << " " << 69 << "\n";
		}
	}
}

Compilation message

minmaxtree.cpp: In function 'int dfs1(int, int, int)':
minmaxtree.cpp:99:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i<adj[now].size(); i++){
                 ~^~~~~~~~~~~~~~~~
minmaxtree.cpp:106:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
minmaxtree.cpp: In function 'std::pair<int, int> go(int, int)':
minmaxtree.cpp:155:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i<adj[now].size(); i++){
                 ~^~~~~~~~~~~~~~~~
minmaxtree.cpp:164:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i<remmax[now].size(); i++){
                 ~^~~~~~~~~~~~~~~~~~~
minmaxtree.cpp:167:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i<remmin[now].size(); i++){
                 ~^~~~~~~~~~~~~~~~~~~
minmaxtree.cpp: In function 'int main()':
minmaxtree.cpp:269:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j = 0; j<f.adj[2+i].size(); j++){
                  ~^~~~~~~~~~~~~~~~~~

Subtask #1
7.0 / 7.0

# 결과 실행 시간 메모리 Grader output
1 Correct 16 ms 15736 KB Output is correct
2 Correct 22 ms 15980 KB Output is correct
3 Correct 20 ms 16000 KB Output is correct
4 Correct 21 ms 16000 KB Output is correct

Subtask #2
22.0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Correct 850 ms 46092 KB Output is correct
2 Correct 697 ms 46092 KB Output is correct
3 Correct 843 ms 46092 KB Output is correct
4 Correct 874 ms 47500 KB Output is correct
5 Correct 795 ms 47500 KB Output is correct
6 Correct 967 ms 47500 KB Output is correct
7 Correct 598 ms 47500 KB Output is correct

Subtask #3
29.0 / 29.0

# 결과 실행 시간 메모리 Grader output
1 Correct 426 ms 47500 KB Output is correct
2 Correct 378 ms 47500 KB Output is correct
3 Correct 426 ms 47500 KB Output is correct
4 Correct 350 ms 47500 KB Output is correct
5 Correct 500 ms 47500 KB Output is correct
6 Correct 557 ms 47500 KB Output is correct
7 Correct 498 ms 47500 KB Output is correct
8 Correct 454 ms 47500 KB Output is correct

Subtask #4
0 / 42.0

# 결과 실행 시간 메모리 Grader output
1 Correct 16 ms 15736 KB Output is correct
2 Correct 22 ms 15980 KB Output is correct
3 Correct 20 ms 16000 KB Output is correct
4 Correct 21 ms 16000 KB Output is correct
5 Correct 850 ms 46092 KB Output is correct
6 Correct 697 ms 46092 KB Output is correct
7 Correct 843 ms 46092 KB Output is correct
8 Correct 874 ms 47500 KB Output is correct
9 Correct 795 ms 47500 KB Output is correct
10 Correct 967 ms 47500 KB Output is correct
11 Correct 598 ms 47500 KB Output is correct
12 Correct 426 ms 47500 KB Output is correct
13 Correct 378 ms 47500 KB Output is correct
14 Correct 426 ms 47500 KB Output is correct
15 Correct 350 ms 47500 KB Output is correct
16 Correct 500 ms 47500 KB Output is correct
17 Correct 557 ms 47500 KB Output is correct
18 Correct 498 ms 47500 KB Output is correct
19 Correct 454 ms 47500 KB Output is correct
20 Correct 828 ms 47500 KB Output is correct
21 Correct 683 ms 47500 KB Output is correct
22 Correct 779 ms 47500 KB Output is correct
23 Correct 787 ms 47500 KB Output is correct
24 Correct 994 ms 51216 KB Output is correct
25 Execution timed out 1077 ms 52644 KB Time limit exceeded
26 Halted 0 ms 0 KB -