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ID题目提交者结果用时内存语言文件大小提交时间测评时间
#111027#6560. Broken Minimum Spanning TreeTobo#WA 4ms9120kbC++202.1kb2023-06-05 15:33:162023-06-05 15:33:21

Judging History

你现在查看的是最新测评结果

  • [2023-08-10 23:21:45]
  • System Update: QOJ starts to keep a history of the judgings of all the submissions.
  • [2023-06-05 15:33:21]
  • 评测
  • 测评结果:WA
  • 用时:4ms
  • 内存:9120kb
  • [2023-06-05 15:33:16]
  • 提交

answer

#include <bits/stdc++.h>
using namespace std;
using i64 = long long;
#define N 3005

int n, m, fa[N], dep[N], rem[N], val[N], tr[N], id[N];
array<int, 4> e[N];
vector<array<int, 3>> adj[N];
void dfs(int cur, int f)
{
    dep[cur] = dep[f] + 1;
    fa[cur] = f;
    for (auto [i, x, d] : adj[cur])
    {
        if (i == f)
            continue;
        val[i] = x;
        id[i] = d;
        dfs(i, cur);
    }
}
int solve(int u, int v, int x)
{
    pair<int, int> s = {-1, -1};
    while (u != v)
    {
        if (dep[u] < dep[v])
            swap(u, v);
        if (s.second == -1 && val[u] > x)
            s = {id[u], val[u]};
        else if (val[u] > x && s.second > val[u])
            s = {id[u], val[u]};
        u = fa[u];
    }
    return s.first;
}
void solve()
{
    cin >> n >> m;
    vector<pair<int, int>> ans;
    for (int i = 1; i <= m; i++)
    {
        cin >> e[i][0] >> e[i][1] >> e[i][2];
        e[i][3] = i;
        if (i < n)
        {
            adj[e[i][0]].push_back({e[i][1], e[i][2], i});
            adj[e[i][1]].push_back({e[i][0], e[i][2], i});
            tr[i] = 1;
        }
    }
    dfs(1, 0);
    sort(e + n, e + m + 1, [&](auto &e1, auto &e2)
         { return e1[2] < e2[2]; });
    for (int i = n; i <= m; i++)
    {
        int s = solve(e[i][0], e[i][1], e[i][2]);
        if (s == -1)
            continue;
        tr[s] = 0, rem[s] = 1;
        ans.push_back({s, e[i][3]});
        tr[i] = 1;
        for (int i = 1; i <= n; i++)
            adj[i].clear();
        for (int j = i; j >= 1; j--)
        {
            if (!tr[i])
                continue;
            adj[e[i][0]].push_back({e[i][1], e[i][2], e[i][3]});
            adj[e[i][1]].push_back({e[i][0], e[i][2], e[i][3]});
        }
        dfs(1, 0);
    }
    cout << ans.size() << '\n';
    for (auto [l, r] : ans)
        cout << l << ' ' << r << '\n';
}
signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int t = 1;
    // cin >> t;
    while (t--)
        solve();
}

详细

Test #1:

score: 100
Accepted
time: 2ms
memory: 3492kb

input:

4 4
1 2 10
2 3 3
3 4 1
1 4 4

output:

1
1 4

result:

ok correct!

Test #2:

score: 0
Accepted
time: 2ms
memory: 3548kb

input:

6 8
1 2 10
2 3 10
3 4 10
4 5 10
5 6 10
6 1 10
1 3 1
4 6 1

output:

2
2 7
5 8

result:

ok correct!

Test #3:

score: 0
Accepted
time: 0ms
memory: 3752kb

input:

2000 1999
1262 1505 968661582
323 1681 787089412
1132 129 88786681
1909 587 762050278
979 1371 230688681
1686 521 980519364
975 191 887826021
869 461 899130441
1433 259 961154249
1718 547 721696188
1254 1042 458319755
1779 267 85751052
1170 813 283230029
309 20 971682908
224 417 255325364
1084 986 7...

output:

0

result:

ok correct!

Test #4:

score: 0
Accepted
time: 2ms
memory: 3616kb

input:

1999 1998
1757 1820 444157563
1757 395 754598547
1757 1571 432619009
1757 1009 456234067
1757 824 935569725
1757 1698 476714469
1757 1420 901765343
1757 1175 225295107
1757 1512 721959801
1757 1585 955067704
1757 1739 635181418
1757 1686 891225461
1757 84 132683224
1757 1696 48915557
1757 1623 42602...

output:

0

result:

ok correct!

Test #5:

score: 0
Accepted
time: 2ms
memory: 3652kb

input:

1999 1998
1345 647 232183406
40 837 279910457
819 857 137486924
255 1378 517489941
827 1565 894953662
1556 1545 898170464
965 877 72248541
1631 298 635713424
895 197 366305735
966 1160 515776809
1870 1638 220711661
1736 220 716014108
1914 1609 759121968
1293 153 272816132
1936 1433 263859075
985 460...

output:

0

result:

ok correct!

Test #6:

score: 0
Accepted
time: 2ms
memory: 3604kb

input:

500 998
105 1 1
105 2 1
105 3 1
105 4 1
105 5 1
105 6 1
105 7 1
105 8 1
105 9 1
105 10 1
105 11 1
105 12 1
105 13 1
105 14 1
105 15 1
105 16 1
105 17 1
105 18 1
105 19 1
105 20 1
105 21 1
105 22 1
105 23 1
105 24 1
105 25 1
105 26 1
105 27 1
105 28 1
105 29 1
105 30 1
105 31 1
105 32 1
105 33 1
105 ...

output:

0

result:

ok correct!

Test #7:

score: 0
Accepted
time: 2ms
memory: 3536kb

input:

500 998
364 1 1
364 2 1
364 3 1
364 4 1
364 5 1
364 6 1
364 7 1
364 8 1
364 9 1
364 10 1
364 11 1
364 12 1
364 13 1
364 14 1
364 15 1
364 16 1
364 17 1
364 18 1
364 19 1
364 20 1
364 21 1
364 22 1
364 23 1
364 24 1
364 25 1
364 26 1
364 27 1
364 28 1
364 29 1
364 30 1
364 31 1
364 32 1
364 33 1
364 ...

output:

0

result:

ok correct!

Test #8:

score: -100
Wrong Answer
time: 4ms
memory: 9120kb

input:

500 998
86 1 2
86 2 2
86 3 2
86 4 2
86 5 2
86 6 2
86 7 2
86 8 2
86 9 2
86 10 2
86 11 2
86 12 2
86 13 2
86 14 2
86 15 2
86 16 2
86 17 2
86 18 2
86 19 2
86 20 2
86 21 2
86 22 2
86 23 2
86 24 2
86 25 2
86 26 2
86 27 2
86 28 2
86 29 2
86 30 2
86 31 2
86 32 2
86 33 2
86 34 2
86 35 2
86 36 2
86 37 2
86 38...

output:

499
496 827
496 842
496 841
496 840
496 839
496 838
496 837
496 836
496 835
496 834
496 833
496 832
496 831
496 830
496 829
496 828
496 843
496 826
496 825
496 824
496 823
496 822
496 821
496 820
496 819
496 818
496 817
496 816
496 815
496 814
496 813
496 812
496 858
496 873
496 872
496 871
496 870
...

result:

wrong answer bad swap 496 842