oj.uz

답안 #554248

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
554248 2022-04-28T04:23:21 Z farhan132 Network (BOI15_net) C++17
100 / 100
 411 ms 48632 KB 
/***Farhan132***/
//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma")
//#pragma GCC optimization ("unroll-loops")
//#pragma GCC optimize("Ofast,fast-math")
 
#include <bits/stdc++.h>
 
 
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
typedef double dd;
typedef vector<ll> vll;
typedef pair<ll , ll> ii;
typedef vector< ii > vii;
typedef pair < pair < ll , ll > , pair < ll , ll > > cm; 
typedef tuple < ll,  ll, ll > tp;
 
#define ff first
#define ss second
#define pb push_back
#define in insert
#define f0(b) for(int i=0;i<(b);i++)
#define f00(b) for(int j=0;j<(b);j++)
#define f1(b) for(int i=1;i<=(b);i++)
#define f11(b) for(int j=1;j<=(b);j++)
#define f2(a,b) for(int i=(a);i<=(b);i++)
#define f22(a,b) for(int j=(a);j<=(b);j++)
#define sf(a) scanf("%lld",&a)
#define sff(a,b) scanf("%lld %lld", &a , &b)
#define pf(a) printf("%lld\n",a)
#define pff(a,b) printf("%lld %lld\n", a , b)
#define bug printf("**!\n")
#define mem(a , b) memset(a, b ,sizeof(a))
#define front_zero(n) __builtin_clzll(n)
#define back_zero(n) __builtin_ctzll(n)
#define total_one(n) __builtin_popcount(n)
#define clean fflush(stdout)
 
//const ll mod =  (ll) 998244353;
const ll mod =  (ll) 1e9 + 7;
const ll maxn = (ll)1e8 + 5;
const int nnn = 1048590;
const int inf = numeric_limits<int>::max()-1;
//const ll INF = numeric_limits<ll>::max()-1;
const ll INF = (ll)1e18;
 
ll dx[]={0,1,0,-1};
ll dy[]={1,0,-1,0};
ll dxx[]={0,1,0,-1,1,1,-1,-1};
ll dyy[]={1,0,-1,0,1,-1,1,-1};
 
bool USACO = 0;
 
mt19937 rng(chrono::system_clock::now().time_since_epoch().count());
 
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
 
template <typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

const ll N = 5e5 + 5;

vector < ll > a;
vector < ll > v[N];

void dfs(ll s, ll p){
    if(v[s].size() == 1) a.pb(s);
    for(auto u : v[s]){
        if(u - p){
            dfs(u, s);
        }
    }
    return;
}

void solve(){

    ll n; cin >> n;

    for(ll i = 1; i < n; i++){
        ll x, y; cin >> x >> y;
        v[x].pb(y);
        v[y].pb(x);
    }

    for(ll i = 1; i <= n; i++){
        if(v[i].size() != 1){
            dfs(i, 0);
            break;
        }
    }
    cout << (a.size() + 1)/2 << '\n';

    for(ll i = 0; i < (a.size()+1)/2; i++){
        cout << a[i] << ' ' << a[ (i + (a.size()/2))%a.size()] << '\n';
    }
  
  return;
}
 
int main() {
    
    
    #ifdef LOCAL
        freopen("in", "r", stdin);
        freopen("out", "w", stdout);
        auto start_time = clock();
    #else 
       ios_base::sync_with_stdio(0); cin.tie(NULL); cout.tie(NULL);
    #endif
 
    //pre(N);
 
    ll T = 1, CT = 0;  //cin >> T; 
 
    while(T--){

        solve();
    }
    #ifdef LOCAL
        auto end_time = clock();
        cerr<< "Execution time: "<<(end_time - start_time)*(int)1e3/CLOCKS_PER_SEC<<" ms\n";
    #endif
 
    return 0;
}

Compilation message

net.cpp: In function 'void solve()':
net.cpp:99:21: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   99 |     for(ll i = 0; i < (a.size()+1)/2; i++){
      |                   ~~^~~~~~~~~~~~~~~~
net.cpp: In function 'int main()':
net.cpp:119:15: warning: unused variable 'CT' [-Wunused-variable]
  119 |     ll T = 1, CT = 0;  //cin >> T;
      |               ^~

Subtask #1
18.0 / 18.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 11988 KB Output is correct
2 Correct 7 ms 11944 KB Output is correct
3 Correct 7 ms 11988 KB Output is correct
4 Correct 6 ms 12072 KB Output is correct
5 Correct 7 ms 11988 KB Output is correct
6 Correct 7 ms 11988 KB Output is correct
7 Correct 6 ms 12032 KB Output is correct
8 Correct 7 ms 11988 KB Output is correct
9 Correct 6 ms 11988 KB Output is correct
10 Correct 7 ms 11988 KB Output is correct
11 Correct 7 ms 12068 KB Output is correct
12 Correct 7 ms 12068 KB Output is correct
13 Correct 6 ms 11988 KB Output is correct
14 Correct 6 ms 11988 KB Output is correct
15 Correct 7 ms 11988 KB Output is correct
16 Correct 6 ms 11988 KB Output is correct
17 Correct 7 ms 12068 KB Output is correct
18 Correct 6 ms 11988 KB Output is correct
19 Correct 6 ms 12068 KB Output is correct
20 Correct 6 ms 11988 KB Output is correct

Subtask #2
45.0 / 45.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 11988 KB Output is correct
2 Correct 7 ms 11944 KB Output is correct
3 Correct 7 ms 11988 KB Output is correct
4 Correct 6 ms 12072 KB Output is correct
5 Correct 7 ms 11988 KB Output is correct
6 Correct 7 ms 11988 KB Output is correct
7 Correct 6 ms 12032 KB Output is correct
8 Correct 7 ms 11988 KB Output is correct
9 Correct 6 ms 11988 KB Output is correct
10 Correct 7 ms 11988 KB Output is correct
11 Correct 7 ms 12068 KB Output is correct
12 Correct 7 ms 12068 KB Output is correct
13 Correct 6 ms 11988 KB Output is correct
14 Correct 6 ms 11988 KB Output is correct
15 Correct 7 ms 11988 KB Output is correct
16 Correct 6 ms 11988 KB Output is correct
17 Correct 7 ms 12068 KB Output is correct
18 Correct 6 ms 11988 KB Output is correct
19 Correct 6 ms 12068 KB Output is correct
20 Correct 6 ms 11988 KB Output is correct
21 Correct 6 ms 11988 KB Output is correct
22 Correct 7 ms 12128 KB Output is correct
23 Correct 8 ms 12244 KB Output is correct
24 Correct 8 ms 12124 KB Output is correct
25 Correct 7 ms 12076 KB Output is correct
26 Correct 7 ms 12116 KB Output is correct
27 Correct 7 ms 12084 KB Output is correct
28 Correct 8 ms 12116 KB Output is correct
29 Correct 7 ms 12116 KB Output is correct
30 Correct 7 ms 11988 KB Output is correct
31 Correct 7 ms 12116 KB Output is correct
32 Correct 7 ms 11988 KB Output is correct
33 Correct 7 ms 11988 KB Output is correct
34 Correct 7 ms 11988 KB Output is correct
35 Correct 7 ms 12072 KB Output is correct
36 Correct 7 ms 12068 KB Output is correct
37 Correct 7 ms 12040 KB Output is correct
38 Correct 8 ms 12072 KB Output is correct
39 Correct 7 ms 11988 KB Output is correct
40 Correct 7 ms 11980 KB Output is correct
41 Correct 7 ms 11988 KB Output is correct
42 Correct 8 ms 12080 KB Output is correct
43 Correct 7 ms 12052 KB Output is correct
44 Correct 7 ms 12116 KB Output is correct
45 Correct 7 ms 11968 KB Output is correct
46 Correct 8 ms 12116 KB Output is correct
47 Correct 6 ms 11988 KB Output is correct
48 Correct 7 ms 12064 KB Output is correct
49 Correct 7 ms 12112 KB Output is correct
50 Correct 7 ms 11988 KB Output is correct
51 Correct 7 ms 11988 KB Output is correct
52 Correct 7 ms 11988 KB Output is correct
53 Correct 8 ms 12244 KB Output is correct
54 Correct 8 ms 11988 KB Output is correct
55 Correct 6 ms 11988 KB Output is correct
56 Correct 7 ms 12048 KB Output is correct
57 Correct 7 ms 12000 KB Output is correct
58 Correct 7 ms 12116 KB Output is correct

Subtask #3
37.0 / 37.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 11988 KB Output is correct
2 Correct 7 ms 11944 KB Output is correct
3 Correct 7 ms 11988 KB Output is correct
4 Correct 6 ms 12072 KB Output is correct
5 Correct 7 ms 11988 KB Output is correct
6 Correct 7 ms 11988 KB Output is correct
7 Correct 6 ms 12032 KB Output is correct
8 Correct 7 ms 11988 KB Output is correct
9 Correct 6 ms 11988 KB Output is correct
10 Correct 7 ms 11988 KB Output is correct
11 Correct 7 ms 12068 KB Output is correct
12 Correct 7 ms 12068 KB Output is correct
13 Correct 6 ms 11988 KB Output is correct
14 Correct 6 ms 11988 KB Output is correct
15 Correct 7 ms 11988 KB Output is correct
16 Correct 6 ms 11988 KB Output is correct
17 Correct 7 ms 12068 KB Output is correct
18 Correct 6 ms 11988 KB Output is correct
19 Correct 6 ms 12068 KB Output is correct
20 Correct 6 ms 11988 KB Output is correct
21 Correct 6 ms 11988 KB Output is correct
22 Correct 7 ms 12128 KB Output is correct
23 Correct 8 ms 12244 KB Output is correct
24 Correct 8 ms 12124 KB Output is correct
25 Correct 7 ms 12076 KB Output is correct
26 Correct 7 ms 12116 KB Output is correct
27 Correct 7 ms 12084 KB Output is correct
28 Correct 8 ms 12116 KB Output is correct
29 Correct 7 ms 12116 KB Output is correct
30 Correct 7 ms 11988 KB Output is correct
31 Correct 7 ms 12116 KB Output is correct
32 Correct 7 ms 11988 KB Output is correct
33 Correct 7 ms 11988 KB Output is correct
34 Correct 7 ms 11988 KB Output is correct
35 Correct 7 ms 12072 KB Output is correct
36 Correct 7 ms 12068 KB Output is correct
37 Correct 7 ms 12040 KB Output is correct
38 Correct 8 ms 12072 KB Output is correct
39 Correct 7 ms 11988 KB Output is correct
40 Correct 7 ms 11980 KB Output is correct
41 Correct 7 ms 11988 KB Output is correct
42 Correct 8 ms 12080 KB Output is correct
43 Correct 7 ms 12052 KB Output is correct
44 Correct 7 ms 12116 KB Output is correct
45 Correct 7 ms 11968 KB Output is correct
46 Correct 8 ms 12116 KB Output is correct
47 Correct 6 ms 11988 KB Output is correct
48 Correct 7 ms 12064 KB Output is correct
49 Correct 7 ms 12112 KB Output is correct
50 Correct 7 ms 11988 KB Output is correct
51 Correct 7 ms 11988 KB Output is correct
52 Correct 7 ms 11988 KB Output is correct
53 Correct 8 ms 12244 KB Output is correct
54 Correct 8 ms 11988 KB Output is correct
55 Correct 6 ms 11988 KB Output is correct
56 Correct 7 ms 12048 KB Output is correct
57 Correct 7 ms 12000 KB Output is correct
58 Correct 7 ms 12116 KB Output is correct
59 Correct 297 ms 40636 KB Output is correct
60 Correct 358 ms 43408 KB Output is correct
61 Correct 6 ms 11988 KB Output is correct
62 Correct 6 ms 12064 KB Output is correct
63 Correct 260 ms 36728 KB Output is correct
64 Correct 8 ms 12500 KB Output is correct
65 Correct 15 ms 13872 KB Output is correct
66 Correct 121 ms 27904 KB Output is correct
67 Correct 411 ms 46844 KB Output is correct
68 Correct 408 ms 48632 KB Output is correct
69 Correct 11 ms 13024 KB Output is correct
70 Correct 76 ms 23448 KB Output is correct
71 Correct 238 ms 45740 KB Output is correct
72 Correct 259 ms 44200 KB Output is correct
73 Correct 72 ms 20056 KB Output is correct
74 Correct 357 ms 41144 KB Output is correct
75 Correct 26 ms 15684 KB Output is correct
76 Correct 255 ms 45424 KB Output is correct
77 Correct 249 ms 45544 KB Output is correct
78 Correct 31 ms 15792 KB Output is correct
79 Correct 404 ms 45304 KB Output is correct
80 Correct 8 ms 12336 KB Output is correct
81 Correct 84 ms 22548 KB Output is correct
82 Correct 309 ms 43148 KB Output is correct
83 Correct 356 ms 41144 KB Output is correct
84 Correct 365 ms 41292 KB Output is correct
85 Correct 365 ms 41216 KB Output is correct
86 Correct 355 ms 43512 KB Output is correct
87 Correct 352 ms 43408 KB Output is correct