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Submission #33608

# Submission time Handle Problem Language Result Execution time Memory
33608 2017-10-30T11:05:00 Z RockyB Shymbulak (IZhO14_shymbulak) C++14
50 / 100
 1469 ms 100368 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)5000 + 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];

int mx;
int d[N][N];
void maxdist() {
	memset(d, -1, sizeof(d));
	for (int i = 1; i <= n; i++) {
		d[i][i] = 0;
		queue <int> q;
		q.push(i);
		while (sz(q)) {
			int v = q.front();
			q.pop();
			mx = max(mx, d[i][v]);
			for (auto to : g[v]) {
				if (d[i][to] == -1) {
					d[i][to] = d[i][v] + 1;
					q.push(to);
				}
			}
		}
	}
}

ll ans;
ll dp[N];
ll solve(int x) {
	queue <int> q;
	q.push(x);
	memset(dp, 0, sizeof(dp));
	dp[x] = 1;
	while (sz(q)) {
		int v = q.front();
		q.pop();
		for (auto to : g[v]) {
			if (d[x][to] > d[x][v]) {
				q.push(to);
				dp[to] += dp[x];
			}
		}
	}
	ll res = 0;
	for (int i = 1; i <= n; i++) {
		if (d[x][i] == mx) res += dp[i];
	}
	return res;
} 
int main() {
	#ifdef IOI2018
		freopen ("in.txt", "r", stdin);
	#endif
	n = get_int();
	for (int i = 1; i <= n; i++) {
		int v = get_int(), u = get_int();
		g[v].pb(u);
		g[u].pb(v);
	}
	maxdist();
	ll ans = 0;
	for (int i = 1; i <= n; i++) {
		ans += solve(i);
	}
	cout << ans / 2;
	ioi
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 100104 KB Output is correct
2 Correct 3 ms 100104 KB Output is correct
3 Correct 6 ms 100104 KB Output is correct
4 Correct 9 ms 100104 KB Output is correct
5 Correct 9 ms 100104 KB Output is correct
6 Correct 3 ms 100104 KB Output is correct
7 Correct 9 ms 100104 KB Output is correct
8 Correct 13 ms 100104 KB Output is correct
9 Correct 0 ms 100104 KB Output is correct
10 Correct 6 ms 100104 KB Output is correct
11 Correct 9 ms 100104 KB Output is correct
12 Correct 13 ms 100104 KB Output is correct
13 Correct 0 ms 100104 KB Output is correct
14 Correct 19 ms 100104 KB Output is correct
15 Correct 9 ms 100104 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 100104 KB Output is correct
2 Correct 36 ms 100104 KB Output is correct
3 Correct 46 ms 100104 KB Output is correct
4 Correct 46 ms 100104 KB Output is correct
5 Correct 1129 ms 100236 KB Output is correct
6 Correct 653 ms 100368 KB Output is correct
7 Correct 1296 ms 100236 KB Output is correct
8 Correct 1376 ms 100236 KB Output is correct
9 Correct 1089 ms 100236 KB Output is correct
10 Correct 1469 ms 100236 KB Output is correct

Subtask #3
0 / 50.0

# Verdict Execution time Memory Grader output
1 Runtime error 0 ms 100104 KB Execution killed with signal 11 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -