oj.uz

답안 #60952

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
60952 2018-07-25T04:11:45 Z spencercompton Min-max tree (BOI18_minmaxtree) C++14
58 / 100
 1000 ms 50844 KB 
#include <bits/stdc++.h>
using namespace std;
class Edge{
public:
	int to, cap, rev;
	Edge(int a, int b, int c){
		to = a;
		cap = b;
		rev = c;
	}
};
class Flow{
public:
	int n = 140010;
	vector<Edge> adj[140010];
	int dist[140010];
	int nxt[140010];
	bool v[140010];
	int li[140010];
	Flow(){

	}
	void add(int i, int j){
		adj[i].push_back(Edge(j,1,adj[j].size()));
		adj[j].push_back(Edge(i,0,adj[i].size()-1));
	}
	int dfs(int now, int f){
		if(now==1){
			return f;
		}
		int did = 0;
		for(; nxt[now]<adj[now].size() && f>0; nxt[now]++){
			int i = nxt[now];
			int to = adj[now][i].to;
			if(adj[now][i].cap>0 && dist[to] == dist[now]+1){
				int ret = dfs(to,min(f,adj[now][i].cap));
				if(ret>0){
					adj[now][i].cap -= ret;
					adj[to][adj[now][i].rev].cap += ret;
					did += ret;
					f -= ret;
				}
			}
			// if(f>0){
			// 	nxt[now]++;
			// }
			// else{
			// 	break;
			// }
		}
		return did;
	}
	int bfs(){
		for(int i = 0; i<n; i++){
			dist[i] = -1;
		}
		dist[0] = 0;
		int point = 1;
		v[0] = false;
		nxt[0] = 0;
		for(int i = 0; i<point; i++){
			int now = li[i];
			for(int j = 0; j<adj[now].size(); 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
			ans += dfs(0,n);
		}
		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];
			}
		}
		cout << (i+1) << " " << (lc[0][i]+1) << " ";
		if(found!=-1){
			cout << found << "\n";
		}
		else if(maxi[i]!=-1){
			cout << maxi[i] << "\n";
		}
		else if(mini[i]!=-1){
			cout << mini[i] << "\n";
		}
		else{
			cout << 69 << "\n";
		}
	}
}

Compilation message

minmaxtree.cpp: In member function 'int Flow::dfs(int, int)':
minmaxtree.cpp:32:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(; nxt[now]<adj[now].size() && f>0; nxt[now]++){
         ~~~~~~~~^~~~~~~~~~~~~~~~
minmaxtree.cpp: In member function 'int Flow::bfs()':
minmaxtree.cpp:63:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int j = 0; j<adj[now].size(); j++){
                   ~^~~~~~~~~~~~~~~~
minmaxtree.cpp: In function 'int dfs1(int, int, int)':
minmaxtree.cpp:98:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i<adj[now].size(); i++){
                 ~^~~~~~~~~~~~~~~~
minmaxtree.cpp:105:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
minmaxtree.cpp: In function 'std::pair<int, int> go(int, int)':
minmaxtree.cpp:154:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i<adj[now].size(); i++){
                 ~^~~~~~~~~~~~~~~~
minmaxtree.cpp:163:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i<remmax[now].size(); i++){
                 ~^~~~~~~~~~~~~~~~~~~
minmaxtree.cpp:166:18: 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:268:19: 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 19 ms 15736 KB Output is correct
2 Correct 17 ms 15844 KB Output is correct
3 Correct 17 ms 15984 KB Output is correct
4 Correct 19 ms 16112 KB Output is correct

Subtask #2
22.0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Correct 801 ms 45756 KB Output is correct
2 Correct 585 ms 45756 KB Output is correct
3 Correct 742 ms 45756 KB Output is correct
4 Correct 753 ms 47116 KB Output is correct
5 Correct 826 ms 47116 KB Output is correct
6 Correct 719 ms 47116 KB Output is correct
7 Correct 585 ms 47116 KB Output is correct

Subtask #3
29.0 / 29.0

# 결과 실행 시간 메모리 Grader output
1 Correct 368 ms 47116 KB Output is correct
2 Correct 364 ms 47116 KB Output is correct
3 Correct 368 ms 47116 KB Output is correct
4 Correct 370 ms 47116 KB Output is correct
5 Correct 519 ms 47116 KB Output is correct
6 Correct 559 ms 47116 KB Output is correct
7 Correct 572 ms 47116 KB Output is correct
8 Correct 437 ms 47116 KB Output is correct

Subtask #4
0 / 42.0

# 결과 실행 시간 메모리 Grader output
1 Correct 19 ms 15736 KB Output is correct
2 Correct 17 ms 15844 KB Output is correct
3 Correct 17 ms 15984 KB Output is correct
4 Correct 19 ms 16112 KB Output is correct
5 Correct 801 ms 45756 KB Output is correct
6 Correct 585 ms 45756 KB Output is correct
7 Correct 742 ms 45756 KB Output is correct
8 Correct 753 ms 47116 KB Output is correct
9 Correct 826 ms 47116 KB Output is correct
10 Correct 719 ms 47116 KB Output is correct
11 Correct 585 ms 47116 KB Output is correct
12 Correct 368 ms 47116 KB Output is correct
13 Correct 364 ms 47116 KB Output is correct
14 Correct 368 ms 47116 KB Output is correct
15 Correct 370 ms 47116 KB Output is correct
16 Correct 519 ms 47116 KB Output is correct
17 Correct 559 ms 47116 KB Output is correct
18 Correct 572 ms 47116 KB Output is correct
19 Correct 437 ms 47116 KB Output is correct
20 Correct 786 ms 47116 KB Output is correct
21 Correct 668 ms 47116 KB Output is correct
22 Correct 683 ms 47116 KB Output is correct
23 Correct 657 ms 47116 KB Output is correct
24 Execution timed out 1063 ms 50844 KB Time limit exceeded
25 Halted 0 ms 0 KB -