답안 #33661

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
33661 2017-10-31T10:30:22 Z RockyB 관광지 (IZhO14_shymbulak) C++14
0 / 100
133 ms 13292 KB
/// In The Name Of God
 
#pragma GCC optimize("Ofast")
#pragma GCC target_("sse,sse2,sse3,sse3,sse4,popcnt,abm,mmx")
 
#include <bits/stdc++.h>
 
#define f first
#define s second
 
#define pb push_back
#define pp pop_back
#define mp make_pair
 
#define sz(x) (int)x.size()
#define sqr(x) ((x) * 1ll * (x))
#define all(x) x.begin(), x.end()
 
#define Kazakhstan ios_base :: sync_with_stdio(0), cin.tie(0), cout.tie(0);
 
#define nl '\n'
#define ioi exit(0);
 
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
 
const int N = (int)2e5 + 7, inf = (int)1e9 + 7, mod = (int)1e9 + 7;
const ll linf = (ll)1e18 + 7;
const int dx[] = {-1, 0, 1, 0, 1, -1, -1, 1}, dy[] = {0, 1, 0, -1, 1, -1, 1, -1};
 
using namespace std;
 
int get__int() {
	char x = getchar();
	int res = 0;
	while (!isdigit(x)) res = res * 10 + x - '0', x = getchar();
	while (isdigit(x)) res = res * 10 + x - '0', x = getchar();
	return res;
}
 
int n;
vector <int> g[N];

vector <int> cycle;
int from[N];
bool was[N], bad[N];
void find_cycle(int v = 1, int p = -1) {
	was[v] = 1;
	from[v] = p;
	for (auto to : g[v]) {
		if (to == p) continue;
		if (was[to] && !sz(cycle)) {
			int x = v;
			while (1) {
				cycle.pb(x);
				bad[x] = 1;
				if (x == to) break;
				x = from[x];
			}
		}
		else if (!was[to]) find_cycle(to, v);
	}
}

ll ans;
int mx;
int dp[N];
void dfs(int v, int p = -1) {
	priority_queue <int> st;
	for (auto to : g[v]) {
		if (to == p || bad[to]) continue;
		dfs(to, v);
		st.push(dp[to]);
		dp[v] = max(dp[v], dp[to] + 1);
	}
	for (int i = 1, cur = 0; i <= min(2, sz(st)); i++, st.pop()) {
		cur += st.top() + 1;
		mx = max(mx, cur);
	}
}
pair <int, int> mxv[N];
void dfs1(int v, int p = - 1) {
	map <int, int> cnt;
	for (auto to : g[v]) {
		if (to == p || bad[to]) continue;
		dfs1(to, v);
		cnt[dp[to]]++;
	}
	mxv[v].s = 1;
	if (sz(cnt)) {
		auto it = --cnt.end();
		mxv[v] = *it;
		if (it -> f == mx) ans += (ll)it -> s * (it -> s - 1) / 2;
		else if (sz(cnt) > 1) {
			pair <int, int> l1 = *it;
			--it;
			pair <int, int> l2 = *it;
			if (l1.f + l2.f == mx) ans += (ll)l1.s * l2.s;
		}
	}
}
int main() {
	#ifdef IOI2018
		freopen ("in.txt", "r", stdin);
		freopen ("C.out", "w", stdout);
	#endif
	Kazakhstan
	cin >> n;
	for (int i = 1; i <= n; i++) {
		int v, u;
		cin >> v >> u;
		g[v].pb(u);
		g[u].pb(v);
	}
	find_cycle();
	for (auto it : cycle) {
		bool ok = 0;
		for (auto to : g[it]) {
			if (!bad[to]) {
				ok = 1;
				break;
			}
		}
		if (ok) dfs(it);
		mx = max(mx, dp[it] + sz(cycle) / 2);
	}
	int sz = sz(cycle), add = sz / 2;
	for (int i = 0; i < add; i++) {
		cycle.pb(cycle[i]);
	}

	if (sz > 3) {
		set <int> st[2];
		for (int i = 0; i < sz(cycle); i++) {
			if (i >= sz) {
				int l = i - sz;
				st[l % 2].erase(dp[cycle[l]] - l);
			}
			if (i >= 2) mx = max(mx, dp[cycle[i]] + i + *st[i % 2].rbegin());
			st[i % 2].insert(dp[cycle[i]] - i);
		}
	}


	for (int i = 1; i <= n; i++) {
		if (dp[i]) {
			if (dp[i] + add == mx) ans += 1 + (sz % 2);
		}
		else if (dp[i] + add == mx) ans++;
	}

	for (auto it : cycle) {
		bool ok = 0;
		for (auto to : g[it]) {
			if (!bad[to]) {
				ok = 1;
				break;
			}
		}
		if (ok) dfs1(it);
 	}
 	if (sz > 3) {
	 	map <int, int> s[2];
		for (int i = 0; i < sz(cycle); i++) {
			if (i >= sz) {
				int l = i - sz;
				s[l % 2][dp[cycle[l]] - l] -= mxv[cycle[l]].s;
				if (s[l % 2][dp[cycle[l]] - l] == 0) s[l % 2].erase(dp[cycle[l]] - l);
			}
			if (i >= 3) {
				if (dp[cycle[i]] + i + s[i % 2].rbegin() -> f == mx) {
					ans += (ll)mxv[cycle[i]].s * s[i % 2].rbegin() -> s;
				}	
			}
			s[i % 2][dp[cycle[i]] - i] += mxv[cycle[i]].s;
		}
	}
	cout << ans;
	ioi
}

Compilation message

shymbulak.cpp:4:0: warning: ignoring #pragma GCC target_ [-Wunknown-pragmas]
 #pragma GCC target_("sse,sse2,sse3,sse3,sse4,popcnt,abm,mmx")
 ^
# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 10388 KB Output is correct
2 Incorrect 3 ms 10388 KB Output isn't correct
3 Halted 0 ms 0 KB -
# 결과 실행 시간 메모리 Grader output
1 Incorrect 3 ms 10388 KB Output isn't correct
2 Halted 0 ms 0 KB -
# 결과 실행 시간 메모리 Grader output
1 Incorrect 133 ms 13292 KB Output isn't correct
2 Halted 0 ms 0 KB -