Submission #88362

#	Time	Username	Problem	Language	Result	Execution time	Memory
88362		dimash241	Shymbulak (IZhO14_shymbulak)	C++17	50 / 100	1577 ms	20472 KiB

shymbulak

# include <stdio.h>
# include <bits/stdc++.h>


#define _USE_MATH_DEFINES_
#define ll long long
#define ld long double
#define Accepted 0
#define pb push_back
#define mp make_pair
#define sz(x) (int)(x.size())
#define every(x) x.begin(),x.end()
#define F first
#define S second
#define For(i,x,y)  for (int i = x; i <= y; i ++) 
#define FOr(i,x,y)  for (int i = x; i >= y; i --)
#define SpeedForce ios_base::sync_with_stdio(0), cin.tie(0)
// ROAD to...                                                                                                                                                                                                                Red

using namespace std;

inline bool isvowel (char c) {
	c = tolower(c);
    if (c == 'a' || c == 'e' || c == 'i' || c == 'y' || c == 'o' || c == 'u') return 1;
    return 0;
}

const double eps = 0.000001;
const ld pi = acos(-1);
const int maxn = 1e7 + 9;
const int mod = 1e9 + 7;
const ll MOD = 1e18 + 9;
const ll INF = 1e18 + 123;
const int inf = 2e9 + 11;
const int mxn = 1e6 + 9;
const int N = 6e5 + 123;                                          
const int M = 22;
const int pri = 997;
const int Magic = 2101;

const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, -1, 0, 1};
 
int n, m, k;
queue < int > q;  
vector < int > g[N];
pair < int, int > get (int v) {
	vector < int > d(n + 1, -1);
	vector < int > cnt(n + 1, 0);
	d[v] = 0;
	cnt[v] = 1;
	q.push(v);
	while (q.size()) {
		int v = q.front();
		q.pop();

		for (auto to : g[v]) {
			if (d[to] == -1) {
				d[to] = d[v] + 1;
				cnt[to] = cnt[v];
				q.push(to);
			} else if (d[to] == d[v] + 1) {
				cnt[to] += cnt[v];
			}
		}
	}

	int mx = -1, ans = 0;
	For (i, 1, n) {
		if (d[i] > mx) {
			mx = d[i];
			ans = cnt[i];
		} else if (d[i] == mx) {
			ans += cnt[i];
		}
	}

	return mp(mx, ans);
}

int main () {               
    cin >> n;
    For (i, 1, n) {
    	int l, r;
    	cin >> l >> r;
    	g[l].pb(r);
    	g[r].pb(l);
    }

    int mx = -1, ans = 0;
    For (i, 1, n) {
    	pair < int, int > cur = get(i);

    	//cout << i << ' ' << cur.F << ' ' << cur.S << '\n';
    	if (cur.F > mx) mx = cur.F, ans = cur.S;
    	else if (cur.F == mx) ans += cur.S;
    }

    cout << ans / 2;
    return Accepted;
}

// Coded By OB

• Subtask 1: 30 / 30
• Subtask 2: 20 / 20
• Subtask 3: 0 / 50