#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define int long long
#define FOR(i, a, b) for (int i = (a); i <= (b); i++)
#define FORD(i, a, b) for (int i = (b); i >= (a); i --)
#define REP(i, a) for (int i = 0; i < (a); ++i)
#define REPD(i, a) for (int i = (a) - 1; i >= 0; --i)
#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)
constexpr ll LINF = (1ll << 60);
constexpr int INF = (1ll << 55);
constexpr int Mod = 1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
/*
Phu Trong from Nguyen Tat Thanh High School for gifted student
*/
template <class X, class Y>
bool minimize(X &x, const Y &y){
X eps = 1e-9;
if (x > y + eps) {x = y; return 1;}
return 0;
}
template <class X, class Y>
bool maximize(X &x, const Y &y){
X eps = 1e-9;
if (x + eps < y) {x = y; return 1;}
return 0;
}
int N, K;
#define MAX 300005
struct Edge{
int u, v, w;
Edge(){}
Edge(int _u, int _v, int _w): u(_u), v(_v), w(_w){}
int other(int x){
return (x ^ u ^ v);
}
} edge[MAX];
vector<int> G[MAX];
vector<int> ret;
pair<bool, int> dfs(int u, int p, int last_w){
int mx = -INF, mn = 0;
//mx khoảng đỉnh xa nhất có thể được bao phủ bởi 1 trạm nằm trong cây con gốc u
//mn khoảng cách xa nhất của đỉnh chưa được bao phủ nằm trong cây con gốc u
for (int&i : G[u]){
int v = edge[i].other(u);
if(v ^ p){
pair<int, int> x = dfs(v, u, edge[i].w);
if (x.first == 0) maximize(mn, x.second);
else maximize(mx, x.second);
}
}
if (mx >= mn){
if(mx - last_w < 0) return make_pair(0, 0);
return make_pair(1, mx - last_w);
}
else{
if (mn + last_w > K){
ret.push_back(u);
if(K - last_w < 0){
return make_pair(0, 0);
}
return make_pair(1, K - last_w);
}
else{
return make_pair(0, mn + last_w);
}
}
}
void process(void){
cin >> N >> K;
for (int i = 1; i < N; ++i){
cin >> edge[i].u >> edge[i].v >> edge[i].w;
G[edge[i].u].emplace_back(i);
G[edge[i].v].emplace_back(i);
}
dfs(1, 0, INF);
cout << (int)ret.size() << '\n';
for (int&i : ret) cout << i << " ";
}
signed main(){
#define name "Whisper"
cin.tie(nullptr) -> sync_with_stdio(false);
//freopen(name".inp", "r", stdin);
//freopen(name".out", "w", stdout);
process();
return (0 ^ 0);
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
173 ms |
36796 KB |
Output is correct |
2 |
Correct |
158 ms |
36792 KB |
Output is correct |
3 |
Correct |
62 ms |
18120 KB |
Output is correct |
4 |
Correct |
173 ms |
36012 KB |
Output is correct |
5 |
Correct |
3 ms |
7516 KB |
Output is correct |
6 |
Correct |
3 ms |
7260 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
7260 KB |
Output is correct |
2 |
Correct |
3 ms |
7516 KB |
Output is correct |
3 |
Correct |
3 ms |
7516 KB |
Output is correct |
4 |
Correct |
3 ms |
7516 KB |
Output is correct |
5 |
Correct |
3 ms |
7516 KB |
Output is correct |
6 |
Correct |
4 ms |
7260 KB |
Output is correct |
7 |
Correct |
3 ms |
7512 KB |
Output is correct |
8 |
Correct |
4 ms |
7516 KB |
Output is correct |
9 |
Correct |
3 ms |
7516 KB |
Output is correct |
10 |
Correct |
3 ms |
7516 KB |
Output is correct |
11 |
Correct |
3 ms |
7516 KB |
Output is correct |
12 |
Correct |
3 ms |
7260 KB |
Output is correct |
13 |
Correct |
3 ms |
7516 KB |
Output is correct |
14 |
Correct |
3 ms |
7516 KB |
Output is correct |
15 |
Correct |
3 ms |
7516 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
7516 KB |
Output is correct |
2 |
Correct |
3 ms |
7516 KB |
Output is correct |
3 |
Correct |
3 ms |
7256 KB |
Output is correct |
4 |
Correct |
3 ms |
7516 KB |
Output is correct |
5 |
Correct |
4 ms |
7260 KB |
Output is correct |
6 |
Correct |
4 ms |
7516 KB |
Output is correct |
7 |
Correct |
4 ms |
7428 KB |
Output is correct |
8 |
Correct |
3 ms |
7260 KB |
Output is correct |
9 |
Correct |
4 ms |
7260 KB |
Output is correct |
10 |
Correct |
4 ms |
7512 KB |
Output is correct |
11 |
Correct |
4 ms |
7516 KB |
Output is correct |
12 |
Correct |
3 ms |
7472 KB |
Output is correct |
13 |
Correct |
3 ms |
7472 KB |
Output is correct |
14 |
Correct |
3 ms |
7256 KB |
Output is correct |
15 |
Correct |
3 ms |
7516 KB |
Output is correct |
16 |
Correct |
3 ms |
7484 KB |
Output is correct |
17 |
Correct |
3 ms |
7516 KB |
Output is correct |
18 |
Correct |
3 ms |
7516 KB |
Output is correct |
19 |
Correct |
3 ms |
7260 KB |
Output is correct |
20 |
Correct |
3 ms |
7512 KB |
Output is correct |
21 |
Correct |
3 ms |
7516 KB |
Output is correct |
22 |
Correct |
3 ms |
7260 KB |
Output is correct |
23 |
Correct |
3 ms |
7516 KB |
Output is correct |
24 |
Correct |
3 ms |
7516 KB |
Output is correct |
25 |
Correct |
3 ms |
7260 KB |
Output is correct |
26 |
Correct |
3 ms |
7512 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
184 ms |
36808 KB |
Output is correct |
2 |
Correct |
75 ms |
21452 KB |
Output is correct |
3 |
Correct |
75 ms |
21948 KB |
Output is correct |
4 |
Correct |
65 ms |
19944 KB |
Output is correct |
5 |
Correct |
4 ms |
7512 KB |
Output is correct |
6 |
Correct |
3 ms |
7516 KB |
Output is correct |
7 |
Correct |
115 ms |
32760 KB |
Output is correct |
8 |
Correct |
145 ms |
32700 KB |
Output is correct |
9 |
Correct |
125 ms |
32956 KB |
Output is correct |
10 |
Correct |
129 ms |
32956 KB |
Output is correct |
11 |
Correct |
159 ms |
36796 KB |
Output is correct |
12 |
Correct |
89 ms |
25036 KB |
Output is correct |
13 |
Correct |
58 ms |
18372 KB |
Output is correct |
14 |
Correct |
84 ms |
23900 KB |
Output is correct |
15 |
Correct |
103 ms |
27328 KB |
Output is correct |
16 |
Correct |
123 ms |
28876 KB |
Output is correct |
17 |
Correct |
90 ms |
25296 KB |
Output is correct |
18 |
Correct |
90 ms |
25032 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
7768 KB |
Output is correct |
2 |
Correct |
3 ms |
7512 KB |
Output is correct |
3 |
Correct |
3 ms |
7516 KB |
Output is correct |
4 |
Correct |
4 ms |
7516 KB |
Output is correct |
5 |
Correct |
4 ms |
7772 KB |
Output is correct |
6 |
Correct |
4 ms |
7772 KB |
Output is correct |
7 |
Correct |
4 ms |
7772 KB |
Output is correct |
8 |
Correct |
4 ms |
7772 KB |
Output is correct |
9 |
Correct |
5 ms |
7772 KB |
Output is correct |
10 |
Correct |
4 ms |
7780 KB |
Output is correct |
11 |
Correct |
4 ms |
7772 KB |
Output is correct |
12 |
Correct |
4 ms |
7512 KB |
Output is correct |
13 |
Correct |
5 ms |
7772 KB |
Output is correct |
14 |
Correct |
4 ms |
7792 KB |
Output is correct |
15 |
Correct |
5 ms |
7768 KB |
Output is correct |
16 |
Correct |
3 ms |
7516 KB |
Output is correct |
17 |
Correct |
3 ms |
7516 KB |
Output is correct |
18 |
Correct |
3 ms |
7516 KB |
Output is correct |
19 |
Correct |
4 ms |
7524 KB |
Output is correct |
20 |
Correct |
3 ms |
7516 KB |
Output is correct |
21 |
Correct |
4 ms |
7768 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
139 ms |
31600 KB |
Output is correct |
2 |
Correct |
133 ms |
30448 KB |
Output is correct |
3 |
Correct |
138 ms |
32012 KB |
Output is correct |
4 |
Correct |
63 ms |
19024 KB |
Output is correct |
5 |
Correct |
163 ms |
44120 KB |
Output is correct |
6 |
Correct |
175 ms |
42664 KB |
Output is correct |
7 |
Correct |
157 ms |
46916 KB |
Output is correct |
8 |
Correct |
160 ms |
46008 KB |
Output is correct |
9 |
Correct |
141 ms |
39888 KB |
Output is correct |
10 |
Correct |
166 ms |
38868 KB |
Output is correct |
11 |
Correct |
180 ms |
49348 KB |
Output is correct |
12 |
Correct |
85 ms |
23892 KB |
Output is correct |
13 |
Correct |
160 ms |
41928 KB |
Output is correct |
14 |
Correct |
175 ms |
37996 KB |
Output is correct |
15 |
Correct |
141 ms |
32340 KB |
Output is correct |
16 |
Correct |
134 ms |
30800 KB |
Output is correct |
17 |
Correct |
119 ms |
30548 KB |
Output is correct |
18 |
Correct |
145 ms |
32344 KB |
Output is correct |
19 |
Correct |
81 ms |
24656 KB |
Output is correct |
20 |
Correct |
63 ms |
17232 KB |
Output is correct |
21 |
Correct |
145 ms |
32336 KB |
Output is correct |