oj.uz

Submission #887500

# Submission time Handle Problem Language Result Execution time Memory
887500 2023-12-14T16:30:13 Z Mher777 Network (BOI15_net) C++17
100 / 100
 338 ms 48012 KB 
/* ----------------------------- Mher777 ----------------------------- */
#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <iomanip>
#include <array>
#include <string>
#include <algorithm>
#include <cmath>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <vector>
#include <stack>
#include <queue>
#include <deque>
#include <bitset>
#include <list>
#include <iterator>
#include <numeric>
#include <complex>
#include <utility>
#include <random>
#include <fstream>
#include <cassert>
using namespace std;

/* -------------------- Typedefs -------------------- */

typedef int itn;
typedef long long ll;
typedef unsigned long long ull;
typedef float fl;
typedef double db;
typedef long double ld;

/* -------------------- Usings -------------------- */

using vi = vector<int>;
using vll = vector<ll>;
using mii = map<int, int>;
using mll = map<ll, ll>;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

/* -------------------- Defines -------------------- */

#define kap map
#define ff first
#define ss second
#define pub push_back
#define pob pop_back
#define puf push_front
#define pof pop_front
#define mpr make_pair
#define yes cout<<"YES\n"
#define no cout<<"NO\n"
#define all(x) (x).begin(), (x).end()

/* -------------------- Constants -------------------- */

const int MAX = int(1e9 + 5);
const ll MAXL = ll(1e18 + 5);
const ll MOD = ll(1e9 + 7);
const ll MOD2 = ll(998244353);
const ll CON = (ll)(911382323);
const ll MOD3 = (ll)(972663749);

/* -------------------- Functions -------------------- */

void fastio() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
}

void precision(int x) {
    cout.setf(ios::fixed | ios::showpoint);
    cout.precision(x);
}

ll gcd(ll a, ll b) {
    while (b) {
        a %= b;
        swap(a, b);
    }
    return a;
}

ll lcm(ll a, ll b) {
    return a / gcd(a, b) * b;
}

ll range_sum(ll a, ll b) {
    ll dif = a - 1, cnt = b - a + 1;
    ll ans = ((b - a + 1) * (b - a + 2)) / 2;
    ans += ((b - a + 1) * dif);
    return ans;
}

string dec_to_bin(ll a) {
    string s = "";
    for (ll i = a; i > 0; ) {
        ll k = i % 2;
        i /= 2;
        char c = k + 48;
        s += c;
    }
    if (a == 0) {
        s = "0";
    }
    reverse(all(s));
    return s;
}

ll bin_to_dec(string s) {
    ll num = 0;
    for (int i = 0; i < s.size(); i++) {
        num *= 2ll;
        num += (s[i] - '0');
    }
    return num;
}

int isPrime(ll a) {
    if (a == 1) return 0;
    for (ll i = 2; i * i <= a; i++) {
        if (a % i == 0) return 0;
    }
    return 1;
}

ll binpow(ll a, ll b) {
    if (!a) return 0;
    ll ans = 1;
    while (b) {
        if (b & 1) {
            ans *= a;
        }
        b >>= 1;
        a *= a;
    }
    return ans;
}

ll binpow_by_mod(ll a, ll b, ll mod) {
    if (!a) return 0;
    ll ans = 1;
    while (b) {
        if (b & 1) {
            ans *= a;
            ans %= mod;
        }
        b >>= 1;
        a *= a;
        a %= mod;
    }
    return ans;
}

/* -------------------- Solution -------------------- */

const int N = 500005;
vi g[N];
vi root;

void dfs(int u = 1, int p = 0) {
    if (g[u].size() == 1) root.pub(u);
    for (auto to : g[u]) {
        if (to != p) dfs(to, u);
    }
}

void slv() {
    int n;
    cin >> n;
    for (int i = 0; i < n - 1; ++i) {
        int x, y;
        cin >> x >> y;
        g[x].pub(y);
        g[y].pub(x);
    }
    dfs();
    int answ = root.size() / 2;
    vector<pii> ans;
    for (int i = 0; i < answ; ++i) {
        ans.pub({ root[i],root[i + answ] });
    }
    if (root.size() % 2) ans.pub({ root[0],root.back() }), ++answ;
    cout << answ << '\n';
    for (auto elem : ans) {
        cout << elem.ff << " " << elem.ss << '\n';
    }
}

void cs() {
    int tstc = 1;
    //cin >> tstc;
    while (tstc--) {
        slv();
    }
}

void precalc() {
    return;
}

int main() {
    fastio();
    precalc();
    //precision(0);
    cs();
    return 0;
}

Compilation message

net.cpp: In function 'll range_sum(ll, ll)':
net.cpp:95:21: warning: unused variable 'cnt' [-Wunused-variable]
   95 |     ll dif = a - 1, cnt = b - a + 1;
      |                     ^~~
net.cpp: In function 'll bin_to_dec(std::string)':
net.cpp:118:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  118 |     for (int i = 0; i < s.size(); i++) {
      |                     ~~^~~~~~~~~~

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 12124 KB Output is correct
2 Correct 3 ms 12376 KB Output is correct
3 Correct 3 ms 12120 KB Output is correct
4 Correct 3 ms 12124 KB Output is correct
5 Correct 3 ms 12376 KB Output is correct
6 Correct 3 ms 12124 KB Output is correct
7 Correct 3 ms 12124 KB Output is correct
8 Correct 3 ms 12124 KB Output is correct
9 Correct 3 ms 12124 KB Output is correct
10 Correct 4 ms 12124 KB Output is correct
11 Correct 3 ms 12124 KB Output is correct
12 Correct 3 ms 12124 KB Output is correct
13 Correct 3 ms 12196 KB Output is correct
14 Correct 3 ms 12124 KB Output is correct
15 Correct 3 ms 12124 KB Output is correct
16 Correct 3 ms 12124 KB Output is correct
17 Correct 3 ms 12124 KB Output is correct
18 Correct 3 ms 12124 KB Output is correct
19 Correct 3 ms 12124 KB Output is correct
20 Correct 3 ms 12124 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 12124 KB Output is correct
2 Correct 3 ms 12376 KB Output is correct
3 Correct 3 ms 12120 KB Output is correct
4 Correct 3 ms 12124 KB Output is correct
5 Correct 3 ms 12376 KB Output is correct
6 Correct 3 ms 12124 KB Output is correct
7 Correct 3 ms 12124 KB Output is correct
8 Correct 3 ms 12124 KB Output is correct
9 Correct 3 ms 12124 KB Output is correct
10 Correct 4 ms 12124 KB Output is correct
11 Correct 3 ms 12124 KB Output is correct
12 Correct 3 ms 12124 KB Output is correct
13 Correct 3 ms 12196 KB Output is correct
14 Correct 3 ms 12124 KB Output is correct
15 Correct 3 ms 12124 KB Output is correct
16 Correct 3 ms 12124 KB Output is correct
17 Correct 3 ms 12124 KB Output is correct
18 Correct 3 ms 12124 KB Output is correct
19 Correct 3 ms 12124 KB Output is correct
20 Correct 3 ms 12124 KB Output is correct
21 Correct 4 ms 12124 KB Output is correct
22 Correct 3 ms 12124 KB Output is correct
23 Correct 3 ms 12124 KB Output is correct
24 Correct 3 ms 12124 KB Output is correct
25 Correct 4 ms 12124 KB Output is correct
26 Correct 3 ms 12124 KB Output is correct
27 Correct 3 ms 12124 KB Output is correct
28 Correct 3 ms 12124 KB Output is correct
29 Correct 3 ms 12124 KB Output is correct
30 Correct 3 ms 12124 KB Output is correct
31 Correct 3 ms 12124 KB Output is correct
32 Correct 3 ms 12124 KB Output is correct
33 Correct 4 ms 12124 KB Output is correct
34 Correct 3 ms 12376 KB Output is correct
35 Correct 3 ms 12124 KB Output is correct
36 Correct 3 ms 12120 KB Output is correct
37 Correct 3 ms 12124 KB Output is correct
38 Correct 3 ms 12124 KB Output is correct
39 Correct 3 ms 12124 KB Output is correct
40 Correct 3 ms 12120 KB Output is correct
41 Correct 3 ms 12120 KB Output is correct
42 Correct 3 ms 12124 KB Output is correct
43 Correct 4 ms 12120 KB Output is correct
44 Correct 3 ms 12376 KB Output is correct
45 Correct 3 ms 12124 KB Output is correct
46 Correct 3 ms 12200 KB Output is correct
47 Correct 3 ms 12124 KB Output is correct
48 Correct 3 ms 12124 KB Output is correct
49 Correct 3 ms 12120 KB Output is correct
50 Correct 3 ms 12124 KB Output is correct
51 Correct 3 ms 12124 KB Output is correct
52 Correct 4 ms 12120 KB Output is correct
53 Correct 3 ms 12124 KB Output is correct
54 Correct 3 ms 12124 KB Output is correct
55 Correct 3 ms 12124 KB Output is correct
56 Correct 3 ms 12124 KB Output is correct
57 Correct 4 ms 12196 KB Output is correct
58 Correct 4 ms 12124 KB Output is correct

Subtask #3
37.0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 12124 KB Output is correct
2 Correct 3 ms 12376 KB Output is correct
3 Correct 3 ms 12120 KB Output is correct
4 Correct 3 ms 12124 KB Output is correct
5 Correct 3 ms 12376 KB Output is correct
6 Correct 3 ms 12124 KB Output is correct
7 Correct 3 ms 12124 KB Output is correct
8 Correct 3 ms 12124 KB Output is correct
9 Correct 3 ms 12124 KB Output is correct
10 Correct 4 ms 12124 KB Output is correct
11 Correct 3 ms 12124 KB Output is correct
12 Correct 3 ms 12124 KB Output is correct
13 Correct 3 ms 12196 KB Output is correct
14 Correct 3 ms 12124 KB Output is correct
15 Correct 3 ms 12124 KB Output is correct
16 Correct 3 ms 12124 KB Output is correct
17 Correct 3 ms 12124 KB Output is correct
18 Correct 3 ms 12124 KB Output is correct
19 Correct 3 ms 12124 KB Output is correct
20 Correct 3 ms 12124 KB Output is correct
21 Correct 4 ms 12124 KB Output is correct
22 Correct 3 ms 12124 KB Output is correct
23 Correct 3 ms 12124 KB Output is correct
24 Correct 3 ms 12124 KB Output is correct
25 Correct 4 ms 12124 KB Output is correct
26 Correct 3 ms 12124 KB Output is correct
27 Correct 3 ms 12124 KB Output is correct
28 Correct 3 ms 12124 KB Output is correct
29 Correct 3 ms 12124 KB Output is correct
30 Correct 3 ms 12124 KB Output is correct
31 Correct 3 ms 12124 KB Output is correct
32 Correct 3 ms 12124 KB Output is correct
33 Correct 4 ms 12124 KB Output is correct
34 Correct 3 ms 12376 KB Output is correct
35 Correct 3 ms 12124 KB Output is correct
36 Correct 3 ms 12120 KB Output is correct
37 Correct 3 ms 12124 KB Output is correct
38 Correct 3 ms 12124 KB Output is correct
39 Correct 3 ms 12124 KB Output is correct
40 Correct 3 ms 12120 KB Output is correct
41 Correct 3 ms 12120 KB Output is correct
42 Correct 3 ms 12124 KB Output is correct
43 Correct 4 ms 12120 KB Output is correct
44 Correct 3 ms 12376 KB Output is correct
45 Correct 3 ms 12124 KB Output is correct
46 Correct 3 ms 12200 KB Output is correct
47 Correct 3 ms 12124 KB Output is correct
48 Correct 3 ms 12124 KB Output is correct
49 Correct 3 ms 12120 KB Output is correct
50 Correct 3 ms 12124 KB Output is correct
51 Correct 3 ms 12124 KB Output is correct
52 Correct 4 ms 12120 KB Output is correct
53 Correct 3 ms 12124 KB Output is correct
54 Correct 3 ms 12124 KB Output is correct
55 Correct 3 ms 12124 KB Output is correct
56 Correct 3 ms 12124 KB Output is correct
57 Correct 4 ms 12196 KB Output is correct
58 Correct 4 ms 12124 KB Output is correct
59 Correct 225 ms 37320 KB Output is correct
60 Correct 256 ms 40120 KB Output is correct
61 Correct 3 ms 12120 KB Output is correct
62 Correct 3 ms 12124 KB Output is correct
63 Correct 173 ms 34900 KB Output is correct
64 Correct 4 ms 12380 KB Output is correct
65 Correct 9 ms 13920 KB Output is correct
66 Correct 85 ms 28040 KB Output is correct
67 Correct 332 ms 47028 KB Output is correct
68 Correct 338 ms 48012 KB Output is correct
69 Correct 8 ms 13148 KB Output is correct
70 Correct 49 ms 21976 KB Output is correct
71 Correct 184 ms 43972 KB Output is correct
72 Correct 196 ms 42704 KB Output is correct
73 Correct 47 ms 19408 KB Output is correct
74 Correct 314 ms 38880 KB Output is correct
75 Correct 17 ms 15504 KB Output is correct
76 Correct 173 ms 43368 KB Output is correct
77 Correct 179 ms 43740 KB Output is correct
78 Correct 18 ms 15448 KB Output is correct
79 Correct 297 ms 45304 KB Output is correct
80 Correct 4 ms 12376 KB Output is correct
81 Correct 54 ms 21740 KB Output is correct
82 Correct 220 ms 41116 KB Output is correct
83 Correct 278 ms 38668 KB Output is correct
84 Correct 235 ms 38728 KB Output is correct
85 Correct 251 ms 38688 KB Output is correct
86 Correct 241 ms 40220 KB Output is correct
87 Correct 296 ms 40220 KB Output is correct