oj.uz

Submission #54185

# Submission time Handle Problem Language Result Execution time Memory
54185 2018-07-02T16:43:50 Z radoslav11 Simurgh (IOI17_simurgh) C++14
100 / 100
 219 ms 61476 KB 
#include <bits/stdc++.h>
#include "simurgh.h"
//#include "Lgrader.cpp"

using namespace std;
template<class T, class T2> inline int chkmax(T &x, const T2 &y) { return x < y ? x = y, 1 : 0; }
template<class T, class T2> inline int chkmin(T &x, const T2 &y) { return x > y ? x = y, 1 : 0; }
const int MAXN = (1 << 20);
const int MAXM = (1 << 18);

struct dsu
{
	int par[MAXN], sz[MAXN];

	void init(int n) 
	{  
		for(int i = 0; i <= n; i++) 
			par[i] = i, sz[i] = 1;
	}

	int root(int x) { return par[x] == x ? x : par[x] = root(par[x]); }

	bool connected(int x, int y) { return root(x) == root(y); }

	void unite(int u, int v)
	{
		u = root(u);
		v = root(v);

		if(u == v) return;
		if(sz[u] < sz[v]) swap(u, v);

		par[v] = u;
		sz[u] += sz[v];
	}
} d;

int m, n;
pair<int, int> ed[MAXM];
vector<pair<int, int> > adj[MAXN];
int dfs_time, low[MAXN], disc[MAXN];
int low_edge[MAXN], ver[MAXN];
int E[MAXN];

int par[MAXN], pe[MAXN];
vector<int> li[MAXM];
vector<int> le, Tr;

bool cmp(int i, int j) { return min(low[ed[i].first], low[ed[i].second]) < min(low[ed[j].first], low[ed[j].second]); }

void tarjan(int u, int pr)
{
	low[u] = disc[u] = ++dfs_time;
	ver[dfs_time] = u;
	low_edge[u] = -1;

	for(auto e: adj[u])
		if(e.first != pr)
		{
			int v = e.first;
			if(!disc[v])
			{
				par[v] = u;
				pe[v] = e.second;
				tarjan(v, u);

				if(chkmin(low[u], low[v])) 
					low_edge[u] = low_edge[v];

				if(disc[u] < low[v])
					E[e.second] = 1;
			}
			else if(chkmin(low[u], disc[v]))
				low_edge[u] = e.second;
		}

	if(low_edge[u] != -1)
		le.push_back(low_edge[u]);

	if(u != pr) Tr.push_back(pe[u]);
}

int R[MAXM];
int initial;

int diff(int rem, int add)
{
	vector<int> tmp;
	for(int e: Tr)
		if(e == rem) tmp.push_back(add);
		else tmp.push_back(e);

	return count_common_roads(tmp) - initial;
}

int cnt_good(vector<int> L)
{
	d.init(::n);
	vector<int> tmp = L;
	for(int i: L)
		d.unite(ed[i].first, ed[i].second);

	int to_rem = 0;
	for(int i: Tr)
		if(!d.connected(ed[i].first, ed[i].second))
			to_rem += E[i], d.unite(ed[i].first, ed[i].second), tmp.push_back(i);

	return count_common_roads(tmp) - to_rem;
}

void rec(vector<int> &l, int sum)
{
	if(sum == 0) 
		return;

	if(l.size() == 1)
	{
		E[l.back()] = 1;
		return;
	}

	vector<int> m1, m2;
	for(int i = 0; i < (int)l.size() / 2; i++) m1.push_back(l[i]);
	for(int i = l.size() / 2; i < (int)l.size(); i++) m2.push_back(l[i]);

	int c1 = cnt_good(m1), c2 = sum - c1;
	rec(m1, c1);
	rec(m2, c2);
}

std::vector<int> find_roads(int n, std::vector<int> u, std::vector<int> v) 
{
	::n = n;
	::m = u.size();
	for(int i = 0; i < ::m; i++)
	{
		ed[i] = {u[i], v[i]};
		adj[u[i]].push_back({v[i], i});
		adj[v[i]].push_back({u[i], i});
		E[i] = -1;
	}	

	tarjan(0, 0);

	sort(le.begin(), le.end());
	le.erase(unique(le.begin(), le.end()), le.end());
	sort(le.begin(), le.end(), cmp);

	initial = count_common_roads(Tr);

	for(int i: le)
	{
		int from = ed[i].first, to = ed[i].second;
		if(disc[from] > disc[to]) swap(from, to);

		while(to != from)
		{
			li[i].push_back(pe[to]);
			to = par[to];
		}

		int has = -1;
		for(int e: li[i])
			if(E[e] != -1)
				has = e;

		if(has != -1)
		{
			int df = diff(has, i);
			if(df == 0) E[i] = E[has];
			else E[i] = E[has] ^ 1;

			for(int e: li[i])
				if(E[e] == -1)
				{
					int df = diff(e, i);
					if(df == 0) E[e] = E[i];
					else E[e] = E[i] ^ 1;
				}
		}
		else
		{
			bool fl = 0;
			for(int e: li[i])
			{
				R[e] = diff(e, i);
				if(R[e]) fl = 1;
			}	

			if(!fl)
			{
				E[i] = 0;
				for(int e: li[i])
					E[e] = 0;
			}
			else
			{
				for(int e: li[i])
					if(R[e])
					{
						if(R[e] == 1) E[i] = 1;
						else E[i] = 0;
						break;
					}
				
				for(int e: li[i])
					if(E[e] == -1)
					{
						int df = R[e];
						if(df == 0) E[e] = E[i];
						else E[e] = E[i] ^ 1;
					}
			}
		}
	}

	for(int i = 0; i < n; i++)
	{
		int cnt = 0;
		vector<int> candidates;

		for(auto e: adj[i])
			if(E[e.second] == -1)
				candidates.push_back(e.second);
	
		cnt = cnt_good(candidates);
		rec(candidates, cnt);
	}

	vector<int> result;
	for(int i = 0; i < ::m; i++)
		if(E[i] == 1) 
			result.push_back(i);

	if(result.size() != ::n - 1) assert(false);

	return result;
}

Compilation message

simurgh.cpp: In function 'std::vector<int> find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:235:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  if(result.size() != ::n - 1) assert(false);
     ~~~~~~~~~~~~~~^~~~~~~~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 28 ms 31096 KB correct
2 Correct 29 ms 31204 KB correct
3 Correct 28 ms 31280 KB correct
4 Correct 29 ms 31424 KB correct
5 Correct 28 ms 31424 KB correct
6 Correct 29 ms 31424 KB correct
7 Correct 29 ms 31424 KB correct
8 Correct 29 ms 31424 KB correct
9 Correct 28 ms 31424 KB correct
10 Correct 27 ms 31540 KB correct
11 Correct 28 ms 31540 KB correct
12 Correct 28 ms 31540 KB correct
13 Correct 29 ms 31540 KB correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 28 ms 31096 KB correct
2 Correct 29 ms 31204 KB correct
3 Correct 28 ms 31280 KB correct
4 Correct 29 ms 31424 KB correct
5 Correct 28 ms 31424 KB correct
6 Correct 29 ms 31424 KB correct
7 Correct 29 ms 31424 KB correct
8 Correct 29 ms 31424 KB correct
9 Correct 28 ms 31424 KB correct
10 Correct 27 ms 31540 KB correct
11 Correct 28 ms 31540 KB correct
12 Correct 28 ms 31540 KB correct
13 Correct 29 ms 31540 KB correct
14 Correct 30 ms 31540 KB correct
15 Correct 30 ms 31540 KB correct
16 Correct 29 ms 31540 KB correct
17 Correct 29 ms 31624 KB correct
18 Correct 30 ms 31624 KB correct
19 Correct 30 ms 31688 KB correct
20 Correct 29 ms 31688 KB correct
21 Correct 35 ms 31688 KB correct
22 Correct 29 ms 31688 KB correct
23 Correct 31 ms 31688 KB correct
24 Correct 32 ms 31696 KB correct
25 Correct 28 ms 31696 KB correct
26 Correct 28 ms 31696 KB correct
27 Correct 30 ms 31696 KB correct
28 Correct 28 ms 31696 KB correct
29 Correct 27 ms 31696 KB correct
30 Correct 29 ms 31696 KB correct
31 Correct 34 ms 31696 KB correct
32 Correct 37 ms 31724 KB correct
33 Correct 29 ms 31808 KB correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 28 ms 31096 KB correct
2 Correct 29 ms 31204 KB correct
3 Correct 28 ms 31280 KB correct
4 Correct 29 ms 31424 KB correct
5 Correct 28 ms 31424 KB correct
6 Correct 29 ms 31424 KB correct
7 Correct 29 ms 31424 KB correct
8 Correct 29 ms 31424 KB correct
9 Correct 28 ms 31424 KB correct
10 Correct 27 ms 31540 KB correct
11 Correct 28 ms 31540 KB correct
12 Correct 28 ms 31540 KB correct
13 Correct 29 ms 31540 KB correct
14 Correct 30 ms 31540 KB correct
15 Correct 30 ms 31540 KB correct
16 Correct 29 ms 31540 KB correct
17 Correct 29 ms 31624 KB correct
18 Correct 30 ms 31624 KB correct
19 Correct 30 ms 31688 KB correct
20 Correct 29 ms 31688 KB correct
21 Correct 35 ms 31688 KB correct
22 Correct 29 ms 31688 KB correct
23 Correct 31 ms 31688 KB correct
24 Correct 32 ms 31696 KB correct
25 Correct 28 ms 31696 KB correct
26 Correct 28 ms 31696 KB correct
27 Correct 30 ms 31696 KB correct
28 Correct 28 ms 31696 KB correct
29 Correct 27 ms 31696 KB correct
30 Correct 29 ms 31696 KB correct
31 Correct 34 ms 31696 KB correct
32 Correct 37 ms 31724 KB correct
33 Correct 29 ms 31808 KB correct
34 Correct 62 ms 33268 KB correct
35 Correct 60 ms 33468 KB correct
36 Correct 57 ms 33468 KB correct
37 Correct 36 ms 33468 KB correct
38 Correct 73 ms 33828 KB correct
39 Correct 58 ms 33900 KB correct
40 Correct 69 ms 33900 KB correct
41 Correct 63 ms 34324 KB correct
42 Correct 81 ms 34536 KB correct
43 Correct 45 ms 34536 KB correct
44 Correct 42 ms 34536 KB correct
45 Correct 47 ms 34536 KB correct
46 Correct 54 ms 34536 KB correct
47 Correct 36 ms 34536 KB correct
48 Correct 31 ms 34536 KB correct
49 Correct 36 ms 34536 KB correct
50 Correct 40 ms 34536 KB correct
51 Correct 44 ms 34536 KB correct
52 Correct 44 ms 34536 KB correct
53 Correct 41 ms 34536 KB correct
54 Correct 59 ms 34912 KB correct
55 Correct 45 ms 34912 KB correct
56 Correct 46 ms 35040 KB correct
57 Correct 43 ms 35040 KB correct

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 30 ms 35040 KB correct
2 Correct 29 ms 35040 KB correct
3 Correct 148 ms 38316 KB correct
4 Correct 196 ms 41004 KB correct
5 Correct 190 ms 41932 KB correct
6 Correct 198 ms 42984 KB correct
7 Correct 156 ms 43664 KB correct
8 Correct 173 ms 44588 KB correct
9 Correct 216 ms 45532 KB correct
10 Correct 219 ms 46568 KB correct
11 Correct 207 ms 47504 KB correct
12 Correct 198 ms 48316 KB correct
13 Correct 31 ms 48316 KB correct
14 Correct 176 ms 49376 KB correct
15 Correct 215 ms 50432 KB correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 28 ms 31096 KB correct
2 Correct 29 ms 31204 KB correct
3 Correct 28 ms 31280 KB correct
4 Correct 29 ms 31424 KB correct
5 Correct 28 ms 31424 KB correct
6 Correct 29 ms 31424 KB correct
7 Correct 29 ms 31424 KB correct
8 Correct 29 ms 31424 KB correct
9 Correct 28 ms 31424 KB correct
10 Correct 27 ms 31540 KB correct
11 Correct 28 ms 31540 KB correct
12 Correct 28 ms 31540 KB correct
13 Correct 29 ms 31540 KB correct
14 Correct 30 ms 31540 KB correct
15 Correct 30 ms 31540 KB correct
16 Correct 29 ms 31540 KB correct
17 Correct 29 ms 31624 KB correct
18 Correct 30 ms 31624 KB correct
19 Correct 30 ms 31688 KB correct
20 Correct 29 ms 31688 KB correct
21 Correct 35 ms 31688 KB correct
22 Correct 29 ms 31688 KB correct
23 Correct 31 ms 31688 KB correct
24 Correct 32 ms 31696 KB correct
25 Correct 28 ms 31696 KB correct
26 Correct 28 ms 31696 KB correct
27 Correct 30 ms 31696 KB correct
28 Correct 28 ms 31696 KB correct
29 Correct 27 ms 31696 KB correct
30 Correct 29 ms 31696 KB correct
31 Correct 34 ms 31696 KB correct
32 Correct 37 ms 31724 KB correct
33 Correct 29 ms 31808 KB correct
34 Correct 62 ms 33268 KB correct
35 Correct 60 ms 33468 KB correct
36 Correct 57 ms 33468 KB correct
37 Correct 36 ms 33468 KB correct
38 Correct 73 ms 33828 KB correct
39 Correct 58 ms 33900 KB correct
40 Correct 69 ms 33900 KB correct
41 Correct 63 ms 34324 KB correct
42 Correct 81 ms 34536 KB correct
43 Correct 45 ms 34536 KB correct
44 Correct 42 ms 34536 KB correct
45 Correct 47 ms 34536 KB correct
46 Correct 54 ms 34536 KB correct
47 Correct 36 ms 34536 KB correct
48 Correct 31 ms 34536 KB correct
49 Correct 36 ms 34536 KB correct
50 Correct 40 ms 34536 KB correct
51 Correct 44 ms 34536 KB correct
52 Correct 44 ms 34536 KB correct
53 Correct 41 ms 34536 KB correct
54 Correct 59 ms 34912 KB correct
55 Correct 45 ms 34912 KB correct
56 Correct 46 ms 35040 KB correct
57 Correct 43 ms 35040 KB correct
58 Correct 30 ms 35040 KB correct
59 Correct 29 ms 35040 KB correct
60 Correct 148 ms 38316 KB correct
61 Correct 196 ms 41004 KB correct
62 Correct 190 ms 41932 KB correct
63 Correct 198 ms 42984 KB correct
64 Correct 156 ms 43664 KB correct
65 Correct 173 ms 44588 KB correct
66 Correct 216 ms 45532 KB correct
67 Correct 219 ms 46568 KB correct
68 Correct 207 ms 47504 KB correct
69 Correct 198 ms 48316 KB correct
70 Correct 31 ms 48316 KB correct
71 Correct 176 ms 49376 KB correct
72 Correct 215 ms 50432 KB correct
73 Correct 31 ms 50432 KB correct
74 Correct 206 ms 51300 KB correct
75 Correct 190 ms 51912 KB correct
76 Correct 107 ms 51912 KB correct
77 Correct 192 ms 53508 KB correct
78 Correct 195 ms 54176 KB correct
79 Correct 209 ms 55112 KB correct
80 Correct 188 ms 56024 KB correct
81 Correct 135 ms 56168 KB correct
82 Correct 187 ms 57568 KB correct
83 Correct 170 ms 57568 KB correct
84 Correct 95 ms 57568 KB correct
85 Correct 92 ms 57568 KB correct
86 Correct 80 ms 57568 KB correct
87 Correct 86 ms 57568 KB correct
88 Correct 67 ms 57568 KB correct
89 Correct 73 ms 57568 KB correct
90 Correct 65 ms 57568 KB correct
91 Correct 46 ms 57568 KB correct
92 Correct 42 ms 57568 KB correct
93 Correct 91 ms 58752 KB correct
94 Correct 78 ms 58752 KB correct
95 Correct 104 ms 58752 KB correct
96 Correct 73 ms 58752 KB correct
97 Correct 77 ms 58752 KB correct
98 Correct 98 ms 58752 KB correct
99 Correct 67 ms 58752 KB correct
100 Correct 57 ms 58752 KB correct
101 Correct 41 ms 58752 KB correct
102 Correct 84 ms 59960 KB correct
103 Correct 94 ms 60576 KB correct
104 Correct 100 ms 60888 KB correct
105 Correct 97 ms 61476 KB correct