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답안 #949398

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
949398 2024-03-19T07:57:29 Z Yang8on Parkovi (COCI22_parkovi) C++14
110 / 110
 1638 ms 39132 KB 
#include <bits/stdc++.h>

#define Yang8on Nguyen_Dinh_Son
#define sonphamay Nguyen_Dinh_Son

#define aothtday "aog"
#define fi(i, a, b) for(int i = a; i <= b; i++)
#define fid(i, a, b) for(int i = a; i >= b; i--)
#define ll long long
#define endl '\n'
#define pii pair<int, ll>
#define pb push_back
#define all(v) v.begin(), v.end()
#define f first
#define s second
#define maxn 200005
#define maxm
#define maxx
#define mod 1000000007
#define base 311
#define ModHas 1000000003ll
#define gb(i, j) ((i >> j) & 1)
#define int long long

using namespace std;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

ll GetRandom(ll l, ll r)
{
    return uniform_int_distribution<ll> (l, r)(rng);
}

const ll oo = 1e18;

int n, k;
ll lim, sl;
ll dis[maxn], reach[maxn], place[maxn];
vector<pii> o[maxn];
/// reach[u] : khoảng cách xa nhất đến 1 đỉnh chưa được bao phủ (gọi đỉnh đấy là u, tức u đến 1 đỉnh
void dfs(int u, int par)
{
    for(pii x : o[u])
    {
        int v = x.f;
        ll w = x.s;

        if(v == par) continue;

        dfs(v, u);

        if(reach[v] + min(w, dis[v]) <= lim) /// (**)
        {
            if(reach[v] + dis[v] > lim) reach[u] = max(reach[u], reach[v] + w);
            dis[u] = min(dis[u], dis[v] + w);
        }
        else
        {
            place[v] = 1, sl ++;
            dis[u] = min(dis[u], w);
        }
    }
}

bool calc(int mid)
{
    fi(i, 1, n) dis[i] = oo, reach[i] = 0, place[i] = 0;

    lim = mid, sl = 0;
    dfs(1, -1);

    if(dis[1] + reach[1] > lim) place[1] = 1, sl ++;

    if(sl > k) return false;
    return true;
}

/// (**): tại sao lại là reach[v] + min(w, dis[v]) chứ không phải reach[v] + dis[v]?

/// nếu reach[v] + min(w, dis[v]) <= lim, tức đến u, nếu reach[v] + dis[v] > lim
/// --> reach[v] sẽ ko được điểm đánh dấu nào bao phủ nữa, thay vào đó ta sẽ tìm đình xa
/// nhất có thể đặt để bao phủ v, khi đó điểm đặt của ta sẽ men theo đường từ v lên u
/// --> từ đấy mà có reach[v] + w <= lim --> vẫn có thể chờ để đặt đỉnh tối ưu hơn, tăng
/// reach[u] lên

void solve()
{
    cin >> n >> k;
    fi(i, 1, n - 1)
    {
        int x, y;
        ll w;
        cin >> x >> y >> w;
        o[x].pb({y, w});
        o[y].pb({x, w});
    }

    int l = 0, r = oo;
    while(l <= r)
    {
        int mid = (l + r) >> 1;

        if(calc(mid)) r = mid - 1;
        else l = mid + 1;
    }

    bool check = calc(l);
    sl = 0;
    fi(i, 1, n) if(place[i]) sl ++;

    cout << l << '\n';

    fi(i, 1, n)
    {
        if(place[i]) cout << i << ' ';
        else if(sl < k) sl ++, cout << i << ' ';
    }
}

signed main()
{
    if(fopen(aothtday".inp", "r"))
    {
        freopen(aothtday".inp","r",stdin);
        freopen(aothtday".out","w",stdout);
    }

    ios_base::sync_with_stdio(0);
    cin.tie(NULL);
    cout.tie(NULL);

    int nTest = 1;
//    cin >> nTest;

    while(nTest --)
    {
        solve();
    }

    return 0;
}

Compilation message

Main.cpp: In function 'void solve()':
Main.cpp:107:10: warning: unused variable 'check' [-Wunused-variable]
  107 |     bool check = calc(l);
      |          ^~~~~
Main.cpp: In function 'int main()':
Main.cpp:124:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  124 |         freopen(aothtday".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:125:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  125 |         freopen(aothtday".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 8792 KB Output is correct
2 Correct 2 ms 8796 KB Output is correct
3 Correct 2 ms 8796 KB Output is correct
4 Correct 2 ms 8796 KB Output is correct
5 Correct 2 ms 8792 KB Output is correct
6 Correct 3 ms 8840 KB Output is correct
7 Correct 2 ms 8796 KB Output is correct
8 Correct 2 ms 8796 KB Output is correct
9 Correct 2 ms 8796 KB Output is correct
10 Correct 2 ms 8812 KB Output is correct
11 Correct 2 ms 8796 KB Output is correct
12 Correct 2 ms 8796 KB Output is correct
13 Correct 2 ms 8796 KB Output is correct
14 Correct 2 ms 8796 KB Output is correct

Subtask #2
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 347 ms 35956 KB Output is correct
2 Correct 371 ms 37972 KB Output is correct
3 Correct 379 ms 24616 KB Output is correct
4 Correct 1201 ms 23512 KB Output is correct
5 Correct 1069 ms 23024 KB Output is correct
6 Correct 981 ms 23124 KB Output is correct
7 Correct 1156 ms 21896 KB Output is correct
8 Correct 1430 ms 22568 KB Output is correct
9 Correct 1117 ms 22908 KB Output is correct
10 Correct 1101 ms 23264 KB Output is correct
11 Correct 840 ms 24872 KB Output is correct
12 Correct 808 ms 24764 KB Output is correct
13 Correct 851 ms 26452 KB Output is correct
14 Correct 783 ms 23296 KB Output is correct
15 Correct 785 ms 22896 KB Output is correct
16 Correct 979 ms 24348 KB Output is correct
17 Correct 705 ms 23580 KB Output is correct

Subtask #3
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 381 ms 38976 KB Output is correct
2 Correct 374 ms 37876 KB Output is correct
3 Correct 381 ms 36180 KB Output is correct
4 Correct 371 ms 36472 KB Output is correct
5 Correct 336 ms 38404 KB Output is correct
6 Correct 395 ms 38200 KB Output is correct
7 Correct 398 ms 39132 KB Output is correct
8 Correct 365 ms 38152 KB Output is correct
9 Correct 358 ms 37968 KB Output is correct
10 Correct 384 ms 37380 KB Output is correct
11 Correct 331 ms 36288 KB Output is correct
12 Correct 372 ms 38748 KB Output is correct
13 Correct 424 ms 39012 KB Output is correct
14 Correct 387 ms 38232 KB Output is correct
15 Correct 345 ms 36432 KB Output is correct
16 Correct 379 ms 35556 KB Output is correct
17 Correct 398 ms 35156 KB Output is correct
18 Correct 357 ms 36852 KB Output is correct
19 Correct 382 ms 36212 KB Output is correct
20 Correct 361 ms 37004 KB Output is correct
21 Correct 340 ms 36296 KB Output is correct

Subtask #4
60.0 / 60.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 8792 KB Output is correct
2 Correct 2 ms 8796 KB Output is correct
3 Correct 2 ms 8796 KB Output is correct
4 Correct 2 ms 8796 KB Output is correct
5 Correct 2 ms 8792 KB Output is correct
6 Correct 3 ms 8840 KB Output is correct
7 Correct 2 ms 8796 KB Output is correct
8 Correct 2 ms 8796 KB Output is correct
9 Correct 2 ms 8796 KB Output is correct
10 Correct 2 ms 8812 KB Output is correct
11 Correct 2 ms 8796 KB Output is correct
12 Correct 2 ms 8796 KB Output is correct
13 Correct 2 ms 8796 KB Output is correct
14 Correct 2 ms 8796 KB Output is correct
15 Correct 347 ms 35956 KB Output is correct
16 Correct 371 ms 37972 KB Output is correct
17 Correct 379 ms 24616 KB Output is correct
18 Correct 1201 ms 23512 KB Output is correct
19 Correct 1069 ms 23024 KB Output is correct
20 Correct 981 ms 23124 KB Output is correct
21 Correct 1156 ms 21896 KB Output is correct
22 Correct 1430 ms 22568 KB Output is correct
23 Correct 1117 ms 22908 KB Output is correct
24 Correct 1101 ms 23264 KB Output is correct
25 Correct 840 ms 24872 KB Output is correct
26 Correct 808 ms 24764 KB Output is correct
27 Correct 851 ms 26452 KB Output is correct
28 Correct 783 ms 23296 KB Output is correct
29 Correct 785 ms 22896 KB Output is correct
30 Correct 979 ms 24348 KB Output is correct
31 Correct 705 ms 23580 KB Output is correct
32 Correct 381 ms 38976 KB Output is correct
33 Correct 374 ms 37876 KB Output is correct
34 Correct 381 ms 36180 KB Output is correct
35 Correct 371 ms 36472 KB Output is correct
36 Correct 336 ms 38404 KB Output is correct
37 Correct 395 ms 38200 KB Output is correct
38 Correct 398 ms 39132 KB Output is correct
39 Correct 365 ms 38152 KB Output is correct
40 Correct 358 ms 37968 KB Output is correct
41 Correct 384 ms 37380 KB Output is correct
42 Correct 331 ms 36288 KB Output is correct
43 Correct 372 ms 38748 KB Output is correct
44 Correct 424 ms 39012 KB Output is correct
45 Correct 387 ms 38232 KB Output is correct
46 Correct 345 ms 36432 KB Output is correct
47 Correct 379 ms 35556 KB Output is correct
48 Correct 398 ms 35156 KB Output is correct
49 Correct 357 ms 36852 KB Output is correct
50 Correct 382 ms 36212 KB Output is correct
51 Correct 361 ms 37004 KB Output is correct
52 Correct 340 ms 36296 KB Output is correct
53 Correct 1057 ms 23392 KB Output is correct
54 Correct 1060 ms 23892 KB Output is correct
55 Correct 1257 ms 24512 KB Output is correct
56 Correct 1496 ms 24076 KB Output is correct
57 Correct 1425 ms 24436 KB Output is correct
58 Correct 1369 ms 23520 KB Output is correct
59 Correct 1571 ms 25144 KB Output is correct
60 Correct 1638 ms 23044 KB Output is correct
61 Correct 1108 ms 21592 KB Output is correct
62 Correct 1396 ms 22156 KB Output is correct
63 Correct 1503 ms 23100 KB Output is correct
64 Correct 1338 ms 23252 KB Output is correct
65 Correct 1570 ms 23380 KB Output is correct
66 Correct 1378 ms 23324 KB Output is correct
67 Correct 1161 ms 22496 KB Output is correct
68 Correct 1414 ms 24572 KB Output is correct
69 Correct 361 ms 37972 KB Output is correct
70 Correct 366 ms 35948 KB Output is correct
71 Correct 397 ms 38740 KB Output is correct
72 Correct 270 ms 23720 KB Output is correct
73 Correct 329 ms 22860 KB Output is correct
74 Correct 290 ms 23224 KB Output is correct
75 Correct 808 ms 25188 KB Output is correct
76 Correct 892 ms 24724 KB Output is correct
77 Correct 741 ms 24400 KB Output is correct
78 Correct 853 ms 23888 KB Output is correct