oj.uz

Submission #144991

# Submission time Handle Problem Language Result Execution time Memory
144991 2019-08-18T10:29:51 Z Vlatko Network (BOI15_net) C++14
100 / 100
 567 ms 48024 KB 
#include <bits/stdc++.h>
using namespace std;

void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifndef ONLINE_JUDGE
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif

typedef long long ll;
typedef pair<int, int> pii;


const int maxn = 500050;

int n;
vector<int> adj[maxn];
vector<int> leaves;
vector<pii> edges;

void dfs(int u, int p) {
    if (adj[u].size() == 1 && adj[u][0] == p) {
        leaves.push_back(u);
    }
    for (int v : adj[u]) {
        if (v != p) {
            dfs(v, u);
        }
    }
}

int main() {
    ios::sync_with_stdio(false); cin.tie(0);
    cin >> n;
    for (int i = 0; i < n-1; ++i) {
        int a, b;
        cin >> a >> b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    for (int src = 1; src <= n; ++src) {
        if (adj[src].size() > 1) {
            dfs(src, -1);
            break;
        }
    }
    int k = leaves.size();
    for (int i = 0; i < k/2 + !!(k%2); ++i) {
        edges.emplace_back(leaves[i], leaves[(i + k/2) % k]);
    }
    cout << edges.size() << '\n';
    for (auto &p : edges) {
        cout << p.first << ' ' << p.second << '\n';
    }
}

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 12024 KB Output is correct
2 Correct 12 ms 12152 KB Output is correct
3 Correct 12 ms 12024 KB Output is correct
4 Correct 12 ms 12156 KB Output is correct
5 Correct 12 ms 12024 KB Output is correct
6 Correct 13 ms 12284 KB Output is correct
7 Correct 13 ms 12152 KB Output is correct
8 Correct 13 ms 12152 KB Output is correct
9 Correct 12 ms 12152 KB Output is correct
10 Correct 12 ms 12024 KB Output is correct
11 Correct 12 ms 12024 KB Output is correct
12 Correct 13 ms 12152 KB Output is correct
13 Correct 13 ms 12024 KB Output is correct
14 Correct 13 ms 12152 KB Output is correct
15 Correct 12 ms 12152 KB Output is correct
16 Correct 12 ms 12124 KB Output is correct
17 Correct 13 ms 12152 KB Output is correct
18 Correct 13 ms 12152 KB Output is correct
19 Correct 12 ms 12152 KB Output is correct
20 Correct 12 ms 12152 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 12024 KB Output is correct
2 Correct 12 ms 12152 KB Output is correct
3 Correct 12 ms 12024 KB Output is correct
4 Correct 12 ms 12156 KB Output is correct
5 Correct 12 ms 12024 KB Output is correct
6 Correct 13 ms 12284 KB Output is correct
7 Correct 13 ms 12152 KB Output is correct
8 Correct 13 ms 12152 KB Output is correct
9 Correct 12 ms 12152 KB Output is correct
10 Correct 12 ms 12024 KB Output is correct
11 Correct 12 ms 12024 KB Output is correct
12 Correct 13 ms 12152 KB Output is correct
13 Correct 13 ms 12024 KB Output is correct
14 Correct 13 ms 12152 KB Output is correct
15 Correct 12 ms 12152 KB Output is correct
16 Correct 12 ms 12124 KB Output is correct
17 Correct 13 ms 12152 KB Output is correct
18 Correct 13 ms 12152 KB Output is correct
19 Correct 12 ms 12152 KB Output is correct
20 Correct 12 ms 12152 KB Output is correct
21 Correct 13 ms 12152 KB Output is correct
22 Correct 14 ms 12284 KB Output is correct
23 Correct 14 ms 12152 KB Output is correct
24 Correct 13 ms 12280 KB Output is correct
25 Correct 13 ms 12156 KB Output is correct
26 Correct 13 ms 12152 KB Output is correct
27 Correct 13 ms 12152 KB Output is correct
28 Correct 13 ms 12152 KB Output is correct
29 Correct 13 ms 12152 KB Output is correct
30 Correct 13 ms 12152 KB Output is correct
31 Correct 16 ms 12152 KB Output is correct
32 Correct 13 ms 12152 KB Output is correct
33 Correct 12 ms 12152 KB Output is correct
34 Correct 12 ms 12152 KB Output is correct
35 Correct 12 ms 12152 KB Output is correct
36 Correct 12 ms 12152 KB Output is correct
37 Correct 12 ms 12152 KB Output is correct
38 Correct 13 ms 12152 KB Output is correct
39 Correct 12 ms 12024 KB Output is correct
40 Correct 12 ms 12152 KB Output is correct
41 Correct 12 ms 12064 KB Output is correct
42 Correct 13 ms 12152 KB Output is correct
43 Correct 13 ms 12152 KB Output is correct
44 Correct 12 ms 12024 KB Output is correct
45 Correct 13 ms 12152 KB Output is correct
46 Correct 13 ms 12152 KB Output is correct
47 Correct 12 ms 12024 KB Output is correct
48 Correct 13 ms 12152 KB Output is correct
49 Correct 13 ms 12152 KB Output is correct
50 Correct 12 ms 12152 KB Output is correct
51 Correct 12 ms 12156 KB Output is correct
52 Correct 12 ms 12160 KB Output is correct
53 Correct 13 ms 12196 KB Output is correct
54 Correct 12 ms 12028 KB Output is correct
55 Correct 12 ms 12124 KB Output is correct
56 Correct 12 ms 12148 KB Output is correct
57 Correct 12 ms 12152 KB Output is correct
58 Correct 13 ms 12152 KB Output is correct

Subtask #3
37.0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 12024 KB Output is correct
2 Correct 12 ms 12152 KB Output is correct
3 Correct 12 ms 12024 KB Output is correct
4 Correct 12 ms 12156 KB Output is correct
5 Correct 12 ms 12024 KB Output is correct
6 Correct 13 ms 12284 KB Output is correct
7 Correct 13 ms 12152 KB Output is correct
8 Correct 13 ms 12152 KB Output is correct
9 Correct 12 ms 12152 KB Output is correct
10 Correct 12 ms 12024 KB Output is correct
11 Correct 12 ms 12024 KB Output is correct
12 Correct 13 ms 12152 KB Output is correct
13 Correct 13 ms 12024 KB Output is correct
14 Correct 13 ms 12152 KB Output is correct
15 Correct 12 ms 12152 KB Output is correct
16 Correct 12 ms 12124 KB Output is correct
17 Correct 13 ms 12152 KB Output is correct
18 Correct 13 ms 12152 KB Output is correct
19 Correct 12 ms 12152 KB Output is correct
20 Correct 12 ms 12152 KB Output is correct
21 Correct 13 ms 12152 KB Output is correct
22 Correct 14 ms 12284 KB Output is correct
23 Correct 14 ms 12152 KB Output is correct
24 Correct 13 ms 12280 KB Output is correct
25 Correct 13 ms 12156 KB Output is correct
26 Correct 13 ms 12152 KB Output is correct
27 Correct 13 ms 12152 KB Output is correct
28 Correct 13 ms 12152 KB Output is correct
29 Correct 13 ms 12152 KB Output is correct
30 Correct 13 ms 12152 KB Output is correct
31 Correct 16 ms 12152 KB Output is correct
32 Correct 13 ms 12152 KB Output is correct
33 Correct 12 ms 12152 KB Output is correct
34 Correct 12 ms 12152 KB Output is correct
35 Correct 12 ms 12152 KB Output is correct
36 Correct 12 ms 12152 KB Output is correct
37 Correct 12 ms 12152 KB Output is correct
38 Correct 13 ms 12152 KB Output is correct
39 Correct 12 ms 12024 KB Output is correct
40 Correct 12 ms 12152 KB Output is correct
41 Correct 12 ms 12064 KB Output is correct
42 Correct 13 ms 12152 KB Output is correct
43 Correct 13 ms 12152 KB Output is correct
44 Correct 12 ms 12024 KB Output is correct
45 Correct 13 ms 12152 KB Output is correct
46 Correct 13 ms 12152 KB Output is correct
47 Correct 12 ms 12024 KB Output is correct
48 Correct 13 ms 12152 KB Output is correct
49 Correct 13 ms 12152 KB Output is correct
50 Correct 12 ms 12152 KB Output is correct
51 Correct 12 ms 12156 KB Output is correct
52 Correct 12 ms 12160 KB Output is correct
53 Correct 13 ms 12196 KB Output is correct
54 Correct 12 ms 12028 KB Output is correct
55 Correct 12 ms 12124 KB Output is correct
56 Correct 12 ms 12148 KB Output is correct
57 Correct 12 ms 12152 KB Output is correct
58 Correct 13 ms 12152 KB Output is correct
59 Correct 401 ms 37316 KB Output is correct
60 Correct 494 ms 40164 KB Output is correct
61 Correct 12 ms 12024 KB Output is correct
62 Correct 13 ms 12152 KB Output is correct
63 Correct 357 ms 34844 KB Output is correct
64 Correct 15 ms 12536 KB Output is correct
65 Correct 26 ms 13944 KB Output is correct
66 Correct 188 ms 27896 KB Output is correct
67 Correct 566 ms 47104 KB Output is correct
68 Correct 558 ms 48024 KB Output is correct
69 Correct 20 ms 13048 KB Output is correct
70 Correct 112 ms 21868 KB Output is correct
71 Correct 378 ms 43916 KB Output is correct
72 Correct 371 ms 42588 KB Output is correct
73 Correct 110 ms 19316 KB Output is correct
74 Correct 500 ms 39060 KB Output is correct
75 Correct 46 ms 15476 KB Output is correct
76 Correct 363 ms 43448 KB Output is correct
77 Correct 352 ms 43660 KB Output is correct
78 Correct 44 ms 15608 KB Output is correct
79 Correct 537 ms 45188 KB Output is correct
80 Correct 15 ms 12280 KB Output is correct
81 Correct 132 ms 21872 KB Output is correct
82 Correct 450 ms 41248 KB Output is correct
83 Correct 495 ms 38704 KB Output is correct
84 Correct 524 ms 38668 KB Output is correct
85 Correct 567 ms 38636 KB Output is correct
86 Correct 548 ms 40380 KB Output is correct
87 Correct 503 ms 40104 KB Output is correct