oj.uz

Submission #60939

# Submission time Handle Problem Language Result Execution time Memory
60939 2018-07-25T03:52:24 Z spencercompton Min-max tree (BOI18_minmaxtree) C++
58 / 100
 1000 ms 51204 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];
	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; ){
			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[adj[now][i].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;
		}
		vector<int> li;
		dist[0] = 0;
		li.push_back(0);
		v[0] = false;
		nxt[0] = 0;
		for(int i = 0; i<li.size(); 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.push_back(to);
					v[to] = false;
					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:31:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(; nxt[now]<adj[now].size() && f>0; ){
         ~~~~~~~~^~~~~~~~~~~~~~~~
minmaxtree.cpp: In member function 'int Flow::bfs()':
minmaxtree.cpp:61:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i = 0; i<li.size(); i++){
                  ~^~~~~~~~~~
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: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

# Verdict Execution time Memory Grader output
1 Correct 21 ms 15736 KB Output is correct
2 Correct 20 ms 15848 KB Output is correct
3 Correct 16 ms 15900 KB Output is correct
4 Correct 17 ms 15900 KB Output is correct

Subtask #2
22.0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 781 ms 45556 KB Output is correct
2 Correct 628 ms 45556 KB Output is correct
3 Correct 699 ms 45556 KB Output is correct
4 Correct 979 ms 47164 KB Output is correct
5 Correct 820 ms 47164 KB Output is correct
6 Correct 643 ms 47164 KB Output is correct
7 Correct 621 ms 47164 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 501 ms 47164 KB Output is correct
2 Correct 372 ms 47164 KB Output is correct
3 Correct 365 ms 47164 KB Output is correct
4 Correct 376 ms 47164 KB Output is correct
5 Correct 568 ms 47164 KB Output is correct
6 Correct 456 ms 47164 KB Output is correct
7 Correct 396 ms 47164 KB Output is correct
8 Correct 418 ms 47164 KB Output is correct

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 15736 KB Output is correct
2 Correct 20 ms 15848 KB Output is correct
3 Correct 16 ms 15900 KB Output is correct
4 Correct 17 ms 15900 KB Output is correct
5 Correct 781 ms 45556 KB Output is correct
6 Correct 628 ms 45556 KB Output is correct
7 Correct 699 ms 45556 KB Output is correct
8 Correct 979 ms 47164 KB Output is correct
9 Correct 820 ms 47164 KB Output is correct
10 Correct 643 ms 47164 KB Output is correct
11 Correct 621 ms 47164 KB Output is correct
12 Correct 501 ms 47164 KB Output is correct
13 Correct 372 ms 47164 KB Output is correct
14 Correct 365 ms 47164 KB Output is correct
15 Correct 376 ms 47164 KB Output is correct
16 Correct 568 ms 47164 KB Output is correct
17 Correct 456 ms 47164 KB Output is correct
18 Correct 396 ms 47164 KB Output is correct
19 Correct 418 ms 47164 KB Output is correct
20 Correct 977 ms 47164 KB Output is correct
21 Correct 596 ms 47164 KB Output is correct
22 Correct 610 ms 47164 KB Output is correct
23 Correct 655 ms 47164 KB Output is correct
24 Execution timed out 1035 ms 51204 KB Time limit exceeded
25 Halted 0 ms 0 KB -