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Submission #371423

# Submission time Handle Problem Language Result Execution time Memory
371423 2021-02-26T15:25:06 Z luciocf Duathlon (APIO18_duathlon) C++14
23 / 100
 198 ms 43932 KB 
#include <bits/stdc++.h>

#define all(x) x.begin(), x.end()
#define ff first
#define ss second

using namespace std;

typedef long long ll;
typedef pair<int, int> pii;

const int maxn = 2e5+10;

int n;

pii edge[maxn];

int in[maxn], low[maxn], tt;
bool mark_edge[maxn], art[maxn];

int sz_bcc[maxn], sz_comp;

vector<vector<int>> bcc;
vector<int> tree[maxn];

vector<pii> grafo[maxn];

stack<int> stk;

void make_component(int last)
{
	bcc.push_back(vector<int>());

	while (!stk.empty())
	{
		int e = stk.top(); stk.pop();

		bcc.back().push_back(e);

		if (e == last) break;
	}
}

void lowlink(int u, bool isroot)
{
	in[u] = low[u] = ++tt;
	++sz_comp;

	bool fwd = 0;

	for (auto pp: grafo[u])
	{
		int v = pp.ff, e = pp.ss;
		if (mark_edge[e]) continue;

		mark_edge[e] = 1;
		stk.push(e);

		if (in[v])
		{
			low[u] = min(low[u], in[v]);
			continue;
		}

		lowlink(v, 0);

		if (isroot ? fwd : (low[v] >= in[u]))
		{
			art[u] = 1;
			make_component(e);
		}

		fwd = 1;
	}
}

int sub[maxn];
bool vis[maxn];

ll ans, dp[maxn];

ll choose2(int x)
{
	return 1ll*x*(x-1)/2ll;
}

ll choose3(int x)
{
	return 1ll*x*(x-1)*(x-2);
}

void dfs(int u, int p)
{
	vis[u] = 1;
	sub[u] = (u <= n ? 1 : sz_bcc[u]);

	for (auto v: tree[u])
	{
		if (v == p) continue;

		dfs(v, u);

		if (u <= n)
		{
			dp[u] += 1ll*sub[u]*sub[v];
			dp[u] += choose2(sz_bcc[v]);
			dp[u] += 1ll*sz_bcc[v]*((ll)tree[v].size()-1);
		}

		sub[u] += sub[v];
		dp[u] += dp[v];
	}
}

void solve(int u, int p)
{
	for (auto v: tree[u])
		ans -= 2ll*(u <= n ? 1 : sz_bcc[u])*dp[v];

	for (auto v: tree[u])
	{
		if (v == p) continue;

		int old_sub_v = sub[v], old_sub_u = sub[u];
		ll old_dp_v = dp[v], old_dp_u = dp[u];

		if (u <= n)
		{
			int sz = sz_bcc[v];

			dp[v] += (dp[u] - dp[v] - 1ll*sub[v]*(sub[u]-sub[v]) - choose2(sz) - 1ll*sz*((ll)tree[v].size()-1));
			dp[u] -= (old_dp_v + 1ll*sub[v]*(sub[u]-sub[v]) + choose2(sz) + 1ll*sz*((ll)tree[v].size()-1));
		}
		else
		{
			int sz = sz_bcc[u];

			dp[v] += (dp[u]-dp[v] + 1ll*sub[v]*(sub[u]-sub[v]) + choose2(sz) + 1ll*sz*((ll)tree[u].size()-1));
			dp[u] -= old_dp_v;
		}

		sub[v] = sub[u];
		sub[u] -= old_sub_v;

		solve(v, u);

		sub[v] = old_sub_v, sub[u] = old_sub_u;
		dp[v] = old_dp_v, dp[u] = old_dp_u; 
	}
}

int main(void)
{
	int m;
	scanf("%d %d", &n, &m);

	for (int i = 1; i <= m; i++)
	{
		int u, v;
		scanf("%d %d", &u, &v);

		grafo[u].push_back({v, i});
		grafo[v].push_back({u, i});

		edge[i] = {u, v};
	}

	for (int i = 1; i <= n; i++)
	{
		if (in[i]) continue;

		sz_comp = 0;

		int l = bcc.size();

		lowlink(i, 1);
		make_component(0);

		int r = bcc.size();

		ans += choose3(sz_comp);

		for (int j = l; j < r; j++)
		{
			vector<int> v;

			for (auto e: bcc[j])
			{
				v.push_back(edge[e].ff);
				v.push_back(edge[e].ss);
			}

			sort(all(v));
			v.erase(unique(all(v)), v.end());

			for (auto u: v)
			{
				if (art[u])
				{
					tree[n+j+1].push_back(u);
					tree[u].push_back(n+j+1);
				}
				else
				{
					sz_bcc[n+j+1]++;
				}
			}
		}
	}

	for (int i = 1; i <= 2*n; i++)
	{
		if (!vis[i] && tree[i].size())
		{
			dfs(i, 0);
			solve(i, 0);
		}
	}

	printf("%lld\n", ans);
}

Compilation message

count_triplets.cpp: In function 'int main()':
count_triplets.cpp:155:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  155 |  scanf("%d %d", &n, &m);
      |  ~~~~~^~~~~~~~~~~~~~~~~
count_triplets.cpp:160:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  160 |   scanf("%d %d", &u, &v);
      |   ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 9708 KB Output is correct
2 Correct 7 ms 9708 KB Output is correct
3 Correct 7 ms 9708 KB Output is correct
4 Correct 7 ms 9708 KB Output is correct
5 Correct 8 ms 9708 KB Output is correct
6 Correct 7 ms 9708 KB Output is correct
7 Incorrect 7 ms 9708 KB Output isn't correct
8 Halted 0 ms 0 KB -

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 9708 KB Output is correct
2 Correct 7 ms 9708 KB Output is correct
3 Correct 7 ms 9708 KB Output is correct
4 Correct 7 ms 9708 KB Output is correct
5 Correct 8 ms 9708 KB Output is correct
6 Correct 7 ms 9708 KB Output is correct
7 Incorrect 7 ms 9708 KB Output isn't correct
8 Halted 0 ms 0 KB -

Subtask #3
0 / 8.0

# Verdict Execution time Memory Grader output
1 Incorrect 198 ms 42908 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 9964 KB Output is correct
2 Correct 8 ms 9964 KB Output is correct
3 Correct 9 ms 9964 KB Output is correct
4 Correct 8 ms 10092 KB Output is correct
5 Correct 8 ms 10092 KB Output is correct
6 Correct 8 ms 10092 KB Output is correct
7 Correct 8 ms 10092 KB Output is correct
8 Correct 8 ms 10092 KB Output is correct
9 Correct 8 ms 9964 KB Output is correct
10 Correct 8 ms 9964 KB Output is correct
11 Correct 8 ms 9964 KB Output is correct
12 Correct 8 ms 9964 KB Output is correct
13 Correct 9 ms 9964 KB Output is correct
14 Correct 8 ms 9964 KB Output is correct
15 Correct 8 ms 9964 KB Output is correct
16 Correct 8 ms 9836 KB Output is correct
17 Correct 7 ms 9964 KB Output is correct
18 Correct 8 ms 9964 KB Output is correct
19 Correct 8 ms 9964 KB Output is correct
20 Correct 8 ms 9964 KB Output is correct

Subtask #5
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 161 ms 29724 KB Output is correct
2 Correct 139 ms 29724 KB Output is correct
3 Correct 141 ms 29724 KB Output is correct
4 Correct 144 ms 29724 KB Output is correct
5 Correct 154 ms 29852 KB Output is correct
6 Correct 190 ms 43932 KB Output is correct
7 Correct 179 ms 39452 KB Output is correct
8 Correct 179 ms 38680 KB Output is correct
9 Correct 166 ms 35632 KB Output is correct
10 Correct 142 ms 29672 KB Output is correct
11 Correct 145 ms 29860 KB Output is correct
12 Correct 155 ms 29724 KB Output is correct
13 Correct 148 ms 29856 KB Output is correct
14 Correct 137 ms 28188 KB Output is correct
15 Correct 123 ms 26524 KB Output is correct
16 Correct 78 ms 21788 KB Output is correct
17 Correct 105 ms 27352 KB Output is correct
18 Correct 93 ms 27344 KB Output is correct
19 Correct 95 ms 27464 KB Output is correct
20 Correct 91 ms 27404 KB Output is correct

Subtask #6
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 9964 KB Output is correct
2 Correct 8 ms 9964 KB Output is correct
3 Incorrect 8 ms 9964 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #7
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 155 ms 29724 KB Output is correct
2 Correct 147 ms 29852 KB Output is correct
3 Incorrect 171 ms 28640 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #8
0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 9708 KB Output is correct
2 Correct 7 ms 9708 KB Output is correct
3 Correct 7 ms 9708 KB Output is correct
4 Correct 7 ms 9708 KB Output is correct
5 Correct 8 ms 9708 KB Output is correct
6 Correct 7 ms 9708 KB Output is correct
7 Incorrect 7 ms 9708 KB Output isn't correct
8 Halted 0 ms 0 KB -

Subtask #9
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 9708 KB Output is correct
2 Correct 7 ms 9708 KB Output is correct
3 Correct 7 ms 9708 KB Output is correct
4 Correct 7 ms 9708 KB Output is correct
5 Correct 8 ms 9708 KB Output is correct
6 Correct 7 ms 9708 KB Output is correct
7 Incorrect 7 ms 9708 KB Output isn't correct
8 Halted 0 ms 0 KB -