#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define all(x) begin(x), end(x)
#define sz(x) (int) (x).size()
#define f first
#define s second
template<class T> bool smin(T& a, T b) {
return b < a ? a = b, 1 : 0;
}
template<class T> bool smax(T& a, T b) {
return b > a ? a = b, 1 : 0;
}
int main() {
cin.tie(0) -> sync_with_stdio(0);
int n; cin >> n;
vector adj(n, vector<int>());
for (int i = 1; i < n; i++) {
int x, y; cin >> x >> y;
adj[--x].push_back(--y);
adj[y].push_back(x);
}
vector<int> d(n), c(n);
auto dfs = [&](int u, int p, auto&& dfs) -> void {
d[u] = 0, c[u] = 1;
for (int v : adj[u]) if (v != p) {
dfs(v, u, dfs);
if (smax(d[u], d[v] + 1)) {
c[u] = c[v];
} else if (d[v] + 1 == d[u]) {
c[u] += c[v];
}
}
}; dfs(0, -1, dfs);
ll hard = 0, cnt = 1;
auto dfs2 = [&](int u, int p, int pd, int pc,
auto&& dfs2) -> void {
vector<pair<ll, ll>> opt;
if (u > 0 || sz(adj[u]) == 1) {
opt.push_back({pd, pc});
}
for (int v : adj[u]) if (v != p) {
opt.push_back({d[v] + 1, c[v]});
}
sort(all(opt), greater<>());
if (sz(adj[u]) >= 3) { // can form nonzero path
ll cur = opt[0].f * (opt[1].f + opt[2].f),
num = 0, ties = 0;
for (auto [k, v] : opt) {
if (k == opt[2].f) ties += v;
}
// case 1: all are distinct
if (opt[0].f != opt[1].f &&
opt[1].f != opt[2].f) {
num = opt[1].s * ties;
}
// case 2: all are the same
else if (opt[0].f == opt[1].f &&
opt[1].f == opt[2].f) {
num = ties * ties;
for (auto [k, v] : opt) {
if (k == opt[2].f) num -= v * v;
}
num /= 2;
}
// case 3: first two are the same
else if (opt[0].f == opt[1].f) {
num = (opt[0].s + opt[1].s) * ties;
}
// case 4: last two are the same
else {
num = ties * ties;
for (auto [k, v] : opt) {
if (k == opt[2].f) num -= v * v;
}
num /= 2;
}
if (smax(hard, cur)) {
cnt = num;
} else if (hard == cur) {
cnt += num;
}
}
// processing parent dist & parent count
ll l1 = 0, l2 = 0, cnt1 = 0, cnt2 = 0;
for (auto [k, v] : opt) {
// all paths will increase by len 1
if (k + 1 > l1) {
swap(l1, l2), swap(cnt1, cnt2);
l1 = k + 1, cnt1 = v;
} else if (k + 1 == l1) {
cnt1 += v;
} else if (k + 1 > l2) {
l2 = k + 1, cnt2 = v;
} else if (k + 1 == l2) {
cnt2 += v;
}
}
for (int v : adj[u]) if (v != p) {
if (d[v] + 2 == l1) {
(c[v] == cnt1) ? dfs2(v, u, l2, cnt2, dfs2) :
dfs2(v, u, l1, cnt1 - c[v], dfs2);
} else {
dfs2(v, u, l1, cnt1, dfs2);
}
}
}; dfs2(0, -1, 0, 1, dfs2);
cout << hard << ' ' << cnt << '\n';
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
0 ms |
348 KB |
Output is correct |
8 |
Correct |
0 ms |
348 KB |
Output is correct |
9 |
Correct |
0 ms |
348 KB |
Output is correct |
10 |
Correct |
1 ms |
344 KB |
Output is correct |
11 |
Correct |
0 ms |
348 KB |
Output is correct |
12 |
Correct |
0 ms |
348 KB |
Output is correct |
13 |
Correct |
0 ms |
348 KB |
Output is correct |
14 |
Correct |
0 ms |
348 KB |
Output is correct |
15 |
Correct |
0 ms |
348 KB |
Output is correct |
16 |
Correct |
1 ms |
348 KB |
Output is correct |
17 |
Correct |
0 ms |
348 KB |
Output is correct |
18 |
Correct |
0 ms |
348 KB |
Output is correct |
19 |
Correct |
0 ms |
348 KB |
Output is correct |
20 |
Correct |
0 ms |
344 KB |
Output is correct |
21 |
Correct |
0 ms |
348 KB |
Output is correct |
22 |
Correct |
0 ms |
348 KB |
Output is correct |
23 |
Correct |
0 ms |
348 KB |
Output is correct |
24 |
Correct |
1 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
0 ms |
348 KB |
Output is correct |
8 |
Correct |
0 ms |
348 KB |
Output is correct |
9 |
Correct |
0 ms |
348 KB |
Output is correct |
10 |
Correct |
1 ms |
344 KB |
Output is correct |
11 |
Correct |
0 ms |
348 KB |
Output is correct |
12 |
Correct |
0 ms |
348 KB |
Output is correct |
13 |
Correct |
0 ms |
348 KB |
Output is correct |
14 |
Correct |
0 ms |
348 KB |
Output is correct |
15 |
Correct |
0 ms |
348 KB |
Output is correct |
16 |
Correct |
1 ms |
348 KB |
Output is correct |
17 |
Correct |
0 ms |
348 KB |
Output is correct |
18 |
Correct |
0 ms |
348 KB |
Output is correct |
19 |
Correct |
0 ms |
348 KB |
Output is correct |
20 |
Correct |
0 ms |
344 KB |
Output is correct |
21 |
Correct |
0 ms |
348 KB |
Output is correct |
22 |
Correct |
0 ms |
348 KB |
Output is correct |
23 |
Correct |
0 ms |
348 KB |
Output is correct |
24 |
Correct |
1 ms |
348 KB |
Output is correct |
25 |
Correct |
3 ms |
1112 KB |
Output is correct |
26 |
Correct |
3 ms |
1116 KB |
Output is correct |
27 |
Correct |
2 ms |
1116 KB |
Output is correct |
28 |
Correct |
2 ms |
1116 KB |
Output is correct |
29 |
Correct |
2 ms |
1116 KB |
Output is correct |
30 |
Correct |
2 ms |
1116 KB |
Output is correct |
31 |
Correct |
2 ms |
1116 KB |
Output is correct |
32 |
Correct |
2 ms |
1112 KB |
Output is correct |
33 |
Correct |
2 ms |
1116 KB |
Output is correct |
34 |
Correct |
2 ms |
1116 KB |
Output is correct |
35 |
Correct |
2 ms |
1116 KB |
Output is correct |
36 |
Correct |
2 ms |
1116 KB |
Output is correct |
37 |
Correct |
2 ms |
1116 KB |
Output is correct |
38 |
Correct |
2 ms |
1628 KB |
Output is correct |
39 |
Correct |
2 ms |
860 KB |
Output is correct |
40 |
Correct |
2 ms |
860 KB |
Output is correct |
41 |
Correct |
2 ms |
604 KB |
Output is correct |
42 |
Correct |
2 ms |
604 KB |
Output is correct |
43 |
Correct |
2 ms |
604 KB |
Output is correct |
44 |
Correct |
2 ms |
604 KB |
Output is correct |
45 |
Correct |
2 ms |
604 KB |
Output is correct |
46 |
Correct |
2 ms |
604 KB |
Output is correct |
47 |
Correct |
2 ms |
860 KB |
Output is correct |
48 |
Correct |
2 ms |
860 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
0 ms |
348 KB |
Output is correct |
8 |
Correct |
0 ms |
348 KB |
Output is correct |
9 |
Correct |
0 ms |
348 KB |
Output is correct |
10 |
Correct |
1 ms |
344 KB |
Output is correct |
11 |
Correct |
0 ms |
348 KB |
Output is correct |
12 |
Correct |
0 ms |
348 KB |
Output is correct |
13 |
Correct |
0 ms |
348 KB |
Output is correct |
14 |
Correct |
0 ms |
348 KB |
Output is correct |
15 |
Correct |
0 ms |
348 KB |
Output is correct |
16 |
Correct |
1 ms |
348 KB |
Output is correct |
17 |
Correct |
0 ms |
348 KB |
Output is correct |
18 |
Correct |
0 ms |
348 KB |
Output is correct |
19 |
Correct |
0 ms |
348 KB |
Output is correct |
20 |
Correct |
0 ms |
344 KB |
Output is correct |
21 |
Correct |
0 ms |
348 KB |
Output is correct |
22 |
Correct |
0 ms |
348 KB |
Output is correct |
23 |
Correct |
0 ms |
348 KB |
Output is correct |
24 |
Correct |
1 ms |
348 KB |
Output is correct |
25 |
Correct |
3 ms |
1112 KB |
Output is correct |
26 |
Correct |
3 ms |
1116 KB |
Output is correct |
27 |
Correct |
2 ms |
1116 KB |
Output is correct |
28 |
Correct |
2 ms |
1116 KB |
Output is correct |
29 |
Correct |
2 ms |
1116 KB |
Output is correct |
30 |
Correct |
2 ms |
1116 KB |
Output is correct |
31 |
Correct |
2 ms |
1116 KB |
Output is correct |
32 |
Correct |
2 ms |
1112 KB |
Output is correct |
33 |
Correct |
2 ms |
1116 KB |
Output is correct |
34 |
Correct |
2 ms |
1116 KB |
Output is correct |
35 |
Correct |
2 ms |
1116 KB |
Output is correct |
36 |
Correct |
2 ms |
1116 KB |
Output is correct |
37 |
Correct |
2 ms |
1116 KB |
Output is correct |
38 |
Correct |
2 ms |
1628 KB |
Output is correct |
39 |
Correct |
2 ms |
860 KB |
Output is correct |
40 |
Correct |
2 ms |
860 KB |
Output is correct |
41 |
Correct |
2 ms |
604 KB |
Output is correct |
42 |
Correct |
2 ms |
604 KB |
Output is correct |
43 |
Correct |
2 ms |
604 KB |
Output is correct |
44 |
Correct |
2 ms |
604 KB |
Output is correct |
45 |
Correct |
2 ms |
604 KB |
Output is correct |
46 |
Correct |
2 ms |
604 KB |
Output is correct |
47 |
Correct |
2 ms |
860 KB |
Output is correct |
48 |
Correct |
2 ms |
860 KB |
Output is correct |
49 |
Correct |
387 ms |
67052 KB |
Output is correct |
50 |
Correct |
386 ms |
73296 KB |
Output is correct |
51 |
Correct |
366 ms |
78928 KB |
Output is correct |
52 |
Correct |
376 ms |
58960 KB |
Output is correct |
53 |
Correct |
352 ms |
76148 KB |
Output is correct |
54 |
Correct |
298 ms |
90464 KB |
Output is correct |
55 |
Correct |
387 ms |
72988 KB |
Output is correct |
56 |
Correct |
309 ms |
80464 KB |
Output is correct |
57 |
Correct |
414 ms |
89992 KB |
Output is correct |
58 |
Correct |
331 ms |
82580 KB |
Output is correct |
59 |
Correct |
347 ms |
82588 KB |
Output is correct |
60 |
Correct |
303 ms |
79004 KB |
Output is correct |
61 |
Correct |
579 ms |
132180 KB |
Output is correct |
62 |
Correct |
590 ms |
115188 KB |
Output is correct |
63 |
Correct |
613 ms |
66048 KB |
Output is correct |
64 |
Correct |
563 ms |
53844 KB |
Output is correct |
65 |
Correct |
566 ms |
46388 KB |
Output is correct |
66 |
Correct |
507 ms |
42580 KB |
Output is correct |
67 |
Correct |
495 ms |
40272 KB |
Output is correct |
68 |
Correct |
570 ms |
39468 KB |
Output is correct |
69 |
Correct |
570 ms |
39248 KB |
Output is correct |
70 |
Correct |
519 ms |
38848 KB |
Output is correct |
71 |
Correct |
491 ms |
38812 KB |
Output is correct |
72 |
Correct |
480 ms |
39152 KB |
Output is correct |
73 |
Correct |
469 ms |
39252 KB |
Output is correct |
74 |
Correct |
519 ms |
39620 KB |
Output is correct |
75 |
Correct |
520 ms |
40136 KB |
Output is correct |
76 |
Correct |
431 ms |
41288 KB |
Output is correct |
77 |
Correct |
423 ms |
44008 KB |
Output is correct |
78 |
Correct |
244 ms |
50640 KB |
Output is correct |