답안 #90252 :: oj.uz

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
90252	2018-12-21T02:34:34 Z	updown1	Network (BOI15_net)	C++17	63 / 100	8 ms	8272 KB

/*
x = total number of nodes
find a node y s.t. the max nodes in any branch is <= floor(x/2)
if x is odd, connect any leaf to y
pair leaves with leaves from different branches greedily taking the biggest two branches
*/
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define For(i, a, b) for(int i=a; i<b; i++)
#define ffi For(i, 0, N)
#define ffj For(j, 0, K)
#define ffa ffi ffj
#define s <<" "<<
#define c <<" : "<<
#define w cout
#define e endl//"\n"
#define pb push_back
#define mp make_pair
#define a first
#define b second
//#define int ll
//500,000,000 operations
const int MAXN = 5000;//00;
//Global Variables
int N, root, x, y, leaves[MAXN], par[MAXN];
vector<int> adj[MAXN];
queue<int> vals[MAXN];
priority_queue<pair<int, int> > take; /// (size of queue, index)

void gol(int p, int at) {
    par[at] = p;
    if (adj[at].size() == 1) {x++; leaves[at] = 1; return;}
    for (int i: adj[at]) if (i != p) {gol(at, i); leaves[at] += leaves[i];}
}
void gorr(int p, int at, int use = -1) {
    if (use == -1 && p != -1) use=at;
    //w<< at+1 s use+1<<e;
    if (adj[at].size() == 1) vals[use].push(at);
    for (int i: adj[at]) if (i != p) gorr(at, i, use);
}

main() {
    //ifstream cin("test.in");
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> N;
    For (i, 1, N) {int a, b; cin >> a >> b; a--; b--; adj[a].pb(b); adj[b].pb(a);}
    ffi if (adj[i].size() != 1) root = i;
    gol(-1, root);
    ffi if (adj[i].size() != 1) {
        bool good;
        if (x-leaves[i] > (x+1)/2) good = false;
        else good = true;
        for (int j: adj[i]) if (j != par[i]) {
            if (leaves[j] > (x+1)/2) good = false;
        }
        if (good) y = i;
    }
    //w<< root+1 s x s y+1<<e;
    /// reroot the tree at y
    root = y;
    gorr(-1, y);
    for (int i: adj[y]) take.push(mp(vals[i].size(), i));
    w<< (x+1)/2<<e;
    For (i, 0, x/2) {
        int a = take.top().b; take.pop();
        int b = take.top().b; take.pop();
        w<< vals[a].front()+1 s vals[b].front()+1<<e;
        vals[a].pop(); vals[b].pop();
        take.push(mp(vals[a].size(), a)); take.push(mp(vals[b].size(), b));
    }
    if (x%2 == 1) {
        int a = take.top().b;
        w<< y+1 s vals[a].front()+1<<e;
    }
}

Compilation message

net.cpp:43:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main() {
      ^

Subtask #1
18.0 / 18.0

#	결과	실행 시간	메모리	Grader output
1	Correct	4 ms	3832 KB	Output is correct
2	Correct	4 ms	3832 KB	Output is correct
3	Correct	4 ms	3856 KB	Output is correct
4	Correct	4 ms	3860 KB	Output is correct
5	Correct	4 ms	3992 KB	Output is correct
6	Correct	4 ms	3992 KB	Output is correct
7	Correct	5 ms	4104 KB	Output is correct
8	Correct	5 ms	4104 KB	Output is correct
9	Correct	5 ms	4104 KB	Output is correct
10	Correct	5 ms	4104 KB	Output is correct
11	Correct	5 ms	4104 KB	Output is correct
12	Correct	5 ms	4284 KB	Output is correct
13	Correct	6 ms	4284 KB	Output is correct
14	Correct	5 ms	4284 KB	Output is correct
15	Correct	4 ms	4284 KB	Output is correct
16	Correct	5 ms	4284 KB	Output is correct
17	Correct	4 ms	4284 KB	Output is correct
18	Correct	5 ms	4284 KB	Output is correct
19	Correct	4 ms	4284 KB	Output is correct
20	Correct	4 ms	4284 KB	Output is correct

Subtask #2
45.0 / 45.0

#	결과	실행 시간	메모리	Grader output
1	Correct	4 ms	3832 KB	Output is correct
2	Correct	4 ms	3832 KB	Output is correct
3	Correct	4 ms	3856 KB	Output is correct
4	Correct	4 ms	3860 KB	Output is correct
5	Correct	4 ms	3992 KB	Output is correct
6	Correct	4 ms	3992 KB	Output is correct
7	Correct	5 ms	4104 KB	Output is correct
8	Correct	5 ms	4104 KB	Output is correct
9	Correct	5 ms	4104 KB	Output is correct
10	Correct	5 ms	4104 KB	Output is correct
11	Correct	5 ms	4104 KB	Output is correct
12	Correct	5 ms	4284 KB	Output is correct
13	Correct	6 ms	4284 KB	Output is correct
14	Correct	5 ms	4284 KB	Output is correct
15	Correct	4 ms	4284 KB	Output is correct
16	Correct	5 ms	4284 KB	Output is correct
17	Correct	4 ms	4284 KB	Output is correct
18	Correct	5 ms	4284 KB	Output is correct
19	Correct	4 ms	4284 KB	Output is correct
20	Correct	4 ms	4284 KB	Output is correct
21	Correct	5 ms	4284 KB	Output is correct
22	Correct	8 ms	4348 KB	Output is correct
23	Correct	7 ms	4380 KB	Output is correct
24	Correct	8 ms	4416 KB	Output is correct
25	Correct	7 ms	4436 KB	Output is correct
26	Correct	5 ms	4452 KB	Output is correct
27	Correct	6 ms	4464 KB	Output is correct
28	Correct	6 ms	4484 KB	Output is correct
29	Correct	6 ms	4504 KB	Output is correct
30	Correct	4 ms	4504 KB	Output is correct
31	Correct	6 ms	4524 KB	Output is correct
32	Correct	5 ms	4524 KB	Output is correct
33	Correct	5 ms	4524 KB	Output is correct
34	Correct	5 ms	4524 KB	Output is correct
35	Correct	5 ms	4524 KB	Output is correct
36	Correct	4 ms	4560 KB	Output is correct
37	Correct	5 ms	4560 KB	Output is correct
38	Correct	5 ms	4560 KB	Output is correct
39	Correct	5 ms	4560 KB	Output is correct
40	Correct	5 ms	4616 KB	Output is correct
41	Correct	5 ms	4616 KB	Output is correct
42	Correct	5 ms	4616 KB	Output is correct
43	Correct	6 ms	4616 KB	Output is correct
44	Correct	5 ms	4616 KB	Output is correct
45	Correct	5 ms	4616 KB	Output is correct
46	Correct	6 ms	4616 KB	Output is correct
47	Correct	5 ms	4616 KB	Output is correct
48	Correct	5 ms	4676 KB	Output is correct
49	Correct	5 ms	4676 KB	Output is correct
50	Correct	4 ms	4676 KB	Output is correct
51	Correct	4 ms	4676 KB	Output is correct
52	Correct	5 ms	4720 KB	Output is correct
53	Correct	5 ms	4720 KB	Output is correct
54	Correct	5 ms	4720 KB	Output is correct
55	Correct	5 ms	4756 KB	Output is correct
56	Correct	5 ms	4756 KB	Output is correct
57	Correct	6 ms	4756 KB	Output is correct
58	Correct	7 ms	4800 KB	Output is correct

Subtask #3
0 / 37.0

#	결과	실행 시간	메모리	Grader output
1	Correct	4 ms	3832 KB	Output is correct
2	Correct	4 ms	3832 KB	Output is correct
3	Correct	4 ms	3856 KB	Output is correct
4	Correct	4 ms	3860 KB	Output is correct
5	Correct	4 ms	3992 KB	Output is correct
6	Correct	4 ms	3992 KB	Output is correct
7	Correct	5 ms	4104 KB	Output is correct
8	Correct	5 ms	4104 KB	Output is correct
9	Correct	5 ms	4104 KB	Output is correct
10	Correct	5 ms	4104 KB	Output is correct
11	Correct	5 ms	4104 KB	Output is correct
12	Correct	5 ms	4284 KB	Output is correct
13	Correct	6 ms	4284 KB	Output is correct
14	Correct	5 ms	4284 KB	Output is correct
15	Correct	4 ms	4284 KB	Output is correct
16	Correct	5 ms	4284 KB	Output is correct
17	Correct	4 ms	4284 KB	Output is correct
18	Correct	5 ms	4284 KB	Output is correct
19	Correct	4 ms	4284 KB	Output is correct
20	Correct	4 ms	4284 KB	Output is correct
21	Correct	5 ms	4284 KB	Output is correct
22	Correct	8 ms	4348 KB	Output is correct
23	Correct	7 ms	4380 KB	Output is correct
24	Correct	8 ms	4416 KB	Output is correct
25	Correct	7 ms	4436 KB	Output is correct
26	Correct	5 ms	4452 KB	Output is correct
27	Correct	6 ms	4464 KB	Output is correct
28	Correct	6 ms	4484 KB	Output is correct
29	Correct	6 ms	4504 KB	Output is correct
30	Correct	4 ms	4504 KB	Output is correct
31	Correct	6 ms	4524 KB	Output is correct
32	Correct	5 ms	4524 KB	Output is correct
33	Correct	5 ms	4524 KB	Output is correct
34	Correct	5 ms	4524 KB	Output is correct
35	Correct	5 ms	4524 KB	Output is correct
36	Correct	4 ms	4560 KB	Output is correct
37	Correct	5 ms	4560 KB	Output is correct
38	Correct	5 ms	4560 KB	Output is correct
39	Correct	5 ms	4560 KB	Output is correct
40	Correct	5 ms	4616 KB	Output is correct
41	Correct	5 ms	4616 KB	Output is correct
42	Correct	5 ms	4616 KB	Output is correct
43	Correct	6 ms	4616 KB	Output is correct
44	Correct	5 ms	4616 KB	Output is correct
45	Correct	5 ms	4616 KB	Output is correct
46	Correct	6 ms	4616 KB	Output is correct
47	Correct	5 ms	4616 KB	Output is correct
48	Correct	5 ms	4676 KB	Output is correct
49	Correct	5 ms	4676 KB	Output is correct
50	Correct	4 ms	4676 KB	Output is correct
51	Correct	4 ms	4676 KB	Output is correct
52	Correct	5 ms	4720 KB	Output is correct
53	Correct	5 ms	4720 KB	Output is correct
54	Correct	5 ms	4720 KB	Output is correct
55	Correct	5 ms	4756 KB	Output is correct
56	Correct	5 ms	4756 KB	Output is correct
57	Correct	6 ms	4756 KB	Output is correct
58	Correct	7 ms	4800 KB	Output is correct
59	Runtime error	8 ms	8272 KB	Execution killed with signal 11 (could be triggered by violating memory limits)
60	Halted	0 ms	0 KB	-

답안 #90252

Compilation message

Subtask #1 18.0 / 18.0

Subtask #2 45.0 / 45.0

Subtask #3 0 / 37.0

Subtask #1
18.0 / 18.0

Subtask #2
45.0 / 45.0

Subtask #3
0 / 37.0