/*
This problem can be found at https://content-available-to-author-only.uz/problem/view/IOI11_race.
SOLUTION
Consider the problem of finding a path of length K containing minimum edges THAT GOES A FIXED NODE x.
This can be done in O(Size of Tree) time. Once this is done, we can remove the node x and edges connected to it. Then we can solve the problem for the remaining connected components.
The best choice of x is the centroid of the tree.
*/
#include "race.h"
#include "bits/stdc++.h"
using namespace std;
const int mxN = 2e5L + 10;
const int mxK = 1e6L + 10;
int n, k;
vector<pair<int, int>> adj[mxN];
int ans = mxN;
int sz[mxN];
bool proc[mxN] = {};
int dp[mxK];
int get_sz(int x, int p) {
sz[x] = 1;
for(auto [y, w] : adj[x]) {
if(proc[y] || y == p) continue;
sz[x] += get_sz(y, x);
}
return sz[x];
}
int get_cen(int x, int p, int tot) {
for(auto [y, w] : adj[x]) {
if(proc[y] || y == p || sz[y] * 2 <= tot) continue;
return get_cen(y, x, tot);
}
return x;
}
void dfs(int x, int p, int dep, int dis, int flag) {
if(dis > k) return;
if(flag == 0) {
if(dp[k - dis] != mxN) ans = min(ans, dep + dp[k - dis]);
}
else if(flag == 1) {
dp[dis] = min(dp[dis], dep);
}
else if(flag == 2) {
dp[dis] = mxN;
}
for(auto [y, w] : adj[x]) {
if(proc[y] || y == p) continue;
dfs(y, x, dep + 1, dis + w, flag);
}
}
void solve(int x = 1, int p = -1) {
int c = get_cen(x, p, get_sz(x, p));
dp[0] = 0;
for(auto [d, w] : adj[c]) {
if(proc[d]) continue;
dfs(d, c, 1, w, 0);
dfs(d, c, 1, w, 1);
}
for(auto [d, w] : adj[c]) {
if(proc[d]) continue;
dfs(d, c, 1, w, 2);
}
dp[0] = mxN;
proc[c] = 1;
for(auto [d, w] : adj[c]) {
if(proc[d]) continue;
solve(d, c);
}
}
int best_path(int N, int K, int H[][2], int L[])
{
for(int i = 0; i < mxK; ++i) dp[i] = mxN;
n = N; k = K;
for(int i = 0; i < n - 1; ++i) {
adj[H[i][0] + 1].emplace_back(H[i][1] + 1, L[i]);
adj[H[i][1] + 1].emplace_back(H[i][0] + 1, L[i]);
}
solve();
return (ans > n - 1 ? -1 : ans);
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
9308 KB |
Output is correct |
2 |
Correct |
3 ms |
9308 KB |
Output is correct |
3 |
Correct |
3 ms |
10844 KB |
Output is correct |
4 |
Correct |
3 ms |
9308 KB |
Output is correct |
5 |
Correct |
5 ms |
9560 KB |
Output is correct |
6 |
Correct |
3 ms |
9308 KB |
Output is correct |
7 |
Correct |
3 ms |
9308 KB |
Output is correct |
8 |
Correct |
3 ms |
10936 KB |
Output is correct |
9 |
Correct |
3 ms |
9308 KB |
Output is correct |
10 |
Correct |
3 ms |
9308 KB |
Output is correct |
11 |
Correct |
2 ms |
9308 KB |
Output is correct |
12 |
Correct |
3 ms |
9308 KB |
Output is correct |
13 |
Correct |
3 ms |
9308 KB |
Output is correct |
14 |
Correct |
3 ms |
10844 KB |
Output is correct |
15 |
Correct |
3 ms |
9308 KB |
Output is correct |
16 |
Correct |
3 ms |
9308 KB |
Output is correct |
17 |
Correct |
3 ms |
9304 KB |
Output is correct |
18 |
Correct |
3 ms |
9308 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
9308 KB |
Output is correct |
2 |
Correct |
3 ms |
9308 KB |
Output is correct |
3 |
Correct |
3 ms |
10844 KB |
Output is correct |
4 |
Correct |
3 ms |
9308 KB |
Output is correct |
5 |
Correct |
5 ms |
9560 KB |
Output is correct |
6 |
Correct |
3 ms |
9308 KB |
Output is correct |
7 |
Correct |
3 ms |
9308 KB |
Output is correct |
8 |
Correct |
3 ms |
10936 KB |
Output is correct |
9 |
Correct |
3 ms |
9308 KB |
Output is correct |
10 |
Correct |
3 ms |
9308 KB |
Output is correct |
11 |
Correct |
2 ms |
9308 KB |
Output is correct |
12 |
Correct |
3 ms |
9308 KB |
Output is correct |
13 |
Correct |
3 ms |
9308 KB |
Output is correct |
14 |
Correct |
3 ms |
10844 KB |
Output is correct |
15 |
Correct |
3 ms |
9308 KB |
Output is correct |
16 |
Correct |
3 ms |
9308 KB |
Output is correct |
17 |
Correct |
3 ms |
9304 KB |
Output is correct |
18 |
Correct |
3 ms |
9308 KB |
Output is correct |
19 |
Correct |
3 ms |
9304 KB |
Output is correct |
20 |
Correct |
4 ms |
9308 KB |
Output is correct |
21 |
Correct |
3 ms |
9308 KB |
Output is correct |
22 |
Correct |
3 ms |
9304 KB |
Output is correct |
23 |
Correct |
3 ms |
9308 KB |
Output is correct |
24 |
Correct |
3 ms |
9308 KB |
Output is correct |
25 |
Correct |
3 ms |
9308 KB |
Output is correct |
26 |
Correct |
3 ms |
9308 KB |
Output is correct |
27 |
Correct |
3 ms |
9400 KB |
Output is correct |
28 |
Correct |
3 ms |
9308 KB |
Output is correct |
29 |
Correct |
4 ms |
9308 KB |
Output is correct |
30 |
Correct |
3 ms |
9308 KB |
Output is correct |
31 |
Correct |
3 ms |
9308 KB |
Output is correct |
32 |
Correct |
4 ms |
9308 KB |
Output is correct |
33 |
Correct |
3 ms |
9308 KB |
Output is correct |
34 |
Correct |
4 ms |
9308 KB |
Output is correct |
35 |
Correct |
3 ms |
9308 KB |
Output is correct |
36 |
Correct |
3 ms |
9320 KB |
Output is correct |
37 |
Correct |
3 ms |
9308 KB |
Output is correct |
38 |
Correct |
4 ms |
9308 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
9308 KB |
Output is correct |
2 |
Correct |
3 ms |
9308 KB |
Output is correct |
3 |
Correct |
3 ms |
10844 KB |
Output is correct |
4 |
Correct |
3 ms |
9308 KB |
Output is correct |
5 |
Correct |
5 ms |
9560 KB |
Output is correct |
6 |
Correct |
3 ms |
9308 KB |
Output is correct |
7 |
Correct |
3 ms |
9308 KB |
Output is correct |
8 |
Correct |
3 ms |
10936 KB |
Output is correct |
9 |
Correct |
3 ms |
9308 KB |
Output is correct |
10 |
Correct |
3 ms |
9308 KB |
Output is correct |
11 |
Correct |
2 ms |
9308 KB |
Output is correct |
12 |
Correct |
3 ms |
9308 KB |
Output is correct |
13 |
Correct |
3 ms |
9308 KB |
Output is correct |
14 |
Correct |
3 ms |
10844 KB |
Output is correct |
15 |
Correct |
3 ms |
9308 KB |
Output is correct |
16 |
Correct |
3 ms |
9308 KB |
Output is correct |
17 |
Correct |
3 ms |
9304 KB |
Output is correct |
18 |
Correct |
3 ms |
9308 KB |
Output is correct |
19 |
Correct |
81 ms |
14608 KB |
Output is correct |
20 |
Correct |
77 ms |
14672 KB |
Output is correct |
21 |
Correct |
86 ms |
14684 KB |
Output is correct |
22 |
Correct |
77 ms |
14680 KB |
Output is correct |
23 |
Correct |
43 ms |
14940 KB |
Output is correct |
24 |
Correct |
34 ms |
14812 KB |
Output is correct |
25 |
Correct |
79 ms |
17376 KB |
Output is correct |
26 |
Correct |
66 ms |
20304 KB |
Output is correct |
27 |
Correct |
90 ms |
21480 KB |
Output is correct |
28 |
Correct |
140 ms |
31060 KB |
Output is correct |
29 |
Correct |
131 ms |
30032 KB |
Output is correct |
30 |
Correct |
89 ms |
21328 KB |
Output is correct |
31 |
Correct |
94 ms |
19912 KB |
Output is correct |
32 |
Correct |
98 ms |
19792 KB |
Output is correct |
33 |
Correct |
150 ms |
20128 KB |
Output is correct |
34 |
Correct |
100 ms |
18512 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
9308 KB |
Output is correct |
2 |
Correct |
3 ms |
9308 KB |
Output is correct |
3 |
Correct |
3 ms |
10844 KB |
Output is correct |
4 |
Correct |
3 ms |
9308 KB |
Output is correct |
5 |
Correct |
5 ms |
9560 KB |
Output is correct |
6 |
Correct |
3 ms |
9308 KB |
Output is correct |
7 |
Correct |
3 ms |
9308 KB |
Output is correct |
8 |
Correct |
3 ms |
10936 KB |
Output is correct |
9 |
Correct |
3 ms |
9308 KB |
Output is correct |
10 |
Correct |
3 ms |
9308 KB |
Output is correct |
11 |
Correct |
2 ms |
9308 KB |
Output is correct |
12 |
Correct |
3 ms |
9308 KB |
Output is correct |
13 |
Correct |
3 ms |
9308 KB |
Output is correct |
14 |
Correct |
3 ms |
10844 KB |
Output is correct |
15 |
Correct |
3 ms |
9308 KB |
Output is correct |
16 |
Correct |
3 ms |
9308 KB |
Output is correct |
17 |
Correct |
3 ms |
9304 KB |
Output is correct |
18 |
Correct |
3 ms |
9308 KB |
Output is correct |
19 |
Correct |
3 ms |
9304 KB |
Output is correct |
20 |
Correct |
4 ms |
9308 KB |
Output is correct |
21 |
Correct |
3 ms |
9308 KB |
Output is correct |
22 |
Correct |
3 ms |
9304 KB |
Output is correct |
23 |
Correct |
3 ms |
9308 KB |
Output is correct |
24 |
Correct |
3 ms |
9308 KB |
Output is correct |
25 |
Correct |
3 ms |
9308 KB |
Output is correct |
26 |
Correct |
3 ms |
9308 KB |
Output is correct |
27 |
Correct |
3 ms |
9400 KB |
Output is correct |
28 |
Correct |
3 ms |
9308 KB |
Output is correct |
29 |
Correct |
4 ms |
9308 KB |
Output is correct |
30 |
Correct |
3 ms |
9308 KB |
Output is correct |
31 |
Correct |
3 ms |
9308 KB |
Output is correct |
32 |
Correct |
4 ms |
9308 KB |
Output is correct |
33 |
Correct |
3 ms |
9308 KB |
Output is correct |
34 |
Correct |
4 ms |
9308 KB |
Output is correct |
35 |
Correct |
3 ms |
9308 KB |
Output is correct |
36 |
Correct |
3 ms |
9320 KB |
Output is correct |
37 |
Correct |
3 ms |
9308 KB |
Output is correct |
38 |
Correct |
4 ms |
9308 KB |
Output is correct |
39 |
Correct |
81 ms |
14608 KB |
Output is correct |
40 |
Correct |
77 ms |
14672 KB |
Output is correct |
41 |
Correct |
86 ms |
14684 KB |
Output is correct |
42 |
Correct |
77 ms |
14680 KB |
Output is correct |
43 |
Correct |
43 ms |
14940 KB |
Output is correct |
44 |
Correct |
34 ms |
14812 KB |
Output is correct |
45 |
Correct |
79 ms |
17376 KB |
Output is correct |
46 |
Correct |
66 ms |
20304 KB |
Output is correct |
47 |
Correct |
90 ms |
21480 KB |
Output is correct |
48 |
Correct |
140 ms |
31060 KB |
Output is correct |
49 |
Correct |
131 ms |
30032 KB |
Output is correct |
50 |
Correct |
89 ms |
21328 KB |
Output is correct |
51 |
Correct |
94 ms |
19912 KB |
Output is correct |
52 |
Correct |
98 ms |
19792 KB |
Output is correct |
53 |
Correct |
150 ms |
20128 KB |
Output is correct |
54 |
Correct |
100 ms |
18512 KB |
Output is correct |
55 |
Correct |
8 ms |
9816 KB |
Output is correct |
56 |
Correct |
11 ms |
9820 KB |
Output is correct |
57 |
Correct |
68 ms |
16356 KB |
Output is correct |
58 |
Correct |
28 ms |
14796 KB |
Output is correct |
59 |
Correct |
67 ms |
20308 KB |
Output is correct |
60 |
Correct |
261 ms |
32080 KB |
Output is correct |
61 |
Correct |
100 ms |
21500 KB |
Output is correct |
62 |
Correct |
113 ms |
19704 KB |
Output is correct |
63 |
Correct |
130 ms |
21508 KB |
Output is correct |
64 |
Correct |
239 ms |
19540 KB |
Output is correct |
65 |
Correct |
96 ms |
21344 KB |
Output is correct |
66 |
Correct |
209 ms |
29680 KB |
Output is correct |
67 |
Correct |
58 ms |
20160 KB |
Output is correct |
68 |
Correct |
124 ms |
20052 KB |
Output is correct |
69 |
Correct |
119 ms |
20048 KB |
Output is correct |
70 |
Correct |
138 ms |
21108 KB |
Output is correct |