oj.uz

Submission #60938

# Submission time Handle Problem Language Result Execution time Memory
60938 2018-07-25T03:51:37 Z spencercompton Min-max tree (BOI18_minmaxtree) C++11
58 / 100
 1000 ms 51132 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 15864 KB Output is correct
2 Correct 20 ms 15900 KB Output is correct
3 Correct 19 ms 16052 KB Output is correct
4 Correct 19 ms 16052 KB Output is correct

Subtask #2
22.0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 828 ms 45592 KB Output is correct
2 Correct 585 ms 45592 KB Output is correct
3 Correct 771 ms 45592 KB Output is correct
4 Correct 932 ms 47192 KB Output is correct
5 Correct 776 ms 47192 KB Output is correct
6 Correct 887 ms 47192 KB Output is correct
7 Correct 698 ms 47192 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 454 ms 47192 KB Output is correct
2 Correct 405 ms 47192 KB Output is correct
3 Correct 390 ms 47192 KB Output is correct
4 Correct 331 ms 47192 KB Output is correct
5 Correct 477 ms 47192 KB Output is correct
6 Correct 474 ms 47192 KB Output is correct
7 Correct 418 ms 47192 KB Output is correct
8 Correct 401 ms 47192 KB Output is correct

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 15864 KB Output is correct
2 Correct 20 ms 15900 KB Output is correct
3 Correct 19 ms 16052 KB Output is correct
4 Correct 19 ms 16052 KB Output is correct
5 Correct 828 ms 45592 KB Output is correct
6 Correct 585 ms 45592 KB Output is correct
7 Correct 771 ms 45592 KB Output is correct
8 Correct 932 ms 47192 KB Output is correct
9 Correct 776 ms 47192 KB Output is correct
10 Correct 887 ms 47192 KB Output is correct
11 Correct 698 ms 47192 KB Output is correct
12 Correct 454 ms 47192 KB Output is correct
13 Correct 405 ms 47192 KB Output is correct
14 Correct 390 ms 47192 KB Output is correct
15 Correct 331 ms 47192 KB Output is correct
16 Correct 477 ms 47192 KB Output is correct
17 Correct 474 ms 47192 KB Output is correct
18 Correct 418 ms 47192 KB Output is correct
19 Correct 401 ms 47192 KB Output is correct
20 Correct 801 ms 47192 KB Output is correct
21 Correct 724 ms 47192 KB Output is correct
22 Correct 764 ms 47192 KB Output is correct
23 Correct 753 ms 47192 KB Output is correct
24 Execution timed out 1083 ms 51132 KB Time limit exceeded
25 Halted 0 ms 0 KB -