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IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#581083#8136. Rebellious Edgeucup-team1766#WA 45ms3836kbC++172.3kb2024-09-22 06:56:352024-09-22 06:56:35

Judging History

你现在查看的是最新测评结果

  • [2024-09-22 06:56:35]
  • 评测
  • 测评结果:WA
  • 用时:45ms
  • 内存:3836kb
  • [2024-09-22 06:56:35]
  • 提交

answer

#include <bits/stdc++.h>
using namespace std;

void solve() {
    int n, m;
    cin >> n >> m;
    vector<vector<pair<int, int>>> graph(n);
    vector<int> min_in(n, INT_MAX);
    int start, end, wb;
    for (int i = 0; i < m; i++) {
        int u, v, w;
        cin >> u >> v >> w;
        u--; v--;
        if (u < v) {
            graph[v].emplace_back(u, w);
            min_in[v] = min(min_in[v], w);
        } else {
            start = u;
            end = v;
            wb = w;
        }
    }

    long long mst1 = 0;
    bool mst1_possible = true;
    for (int i = 1; i < n; i++) {
        if (min_in[i] == INT_MAX) {
            mst1_possible = false;
            break;
        }
        mst1 += min_in[i];
    }

    vector<int> chain_id(n);
    vector<int> prev_node(n);
    chain_id[0] = 1;
    chain_id[end] = 2;
    long long mst2 = wb;
    for (int i = 1; i < n; i++) {
        if (i != end) {
            int min_edge = INT_MAX;
            int p_node = -1;
            for (auto [prev, w] : graph[i]) {
                if (w < min_edge) {
                    min_edge = w;
                    p_node = prev;
                }
            }
            mst2 += min_edge;
            chain_id[i] = chain_id[p_node];
            prev_node[i] = p_node;
        }
    }

    bool mst2_possible = true;
    if (chain_id[start] == 2) {
        vector<bool> valid(n);
        int cur = start;
        while (cur != end) {
            valid[cur] = true;
            cur = prev_node[cur];
        }
        int min_change = INT_MAX;
        for (int i = end + 1; i <= start; i++) {
            if (valid[i]) {
                for (auto [prev, w] : graph[i]) {
                    if (chain_id[prev] == 1) {
                        min_change = min(min_change, w - min_in[i]);
                    }
                }
            }
        }
        if (min_change == INT_MAX) {
            mst2_possible = false;
        } else {
            mst2 += min_change;
        }
    }

    long long res = mst1;
    if (!mst1_possible || (mst2_possible && mst2 < mst1)) {
        res = mst2;
    }
    cout << res << "\n";
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int t;
    cin >> t;
    while (t--) {
        solve();
    }
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 0ms
memory: 3528kb

input:

3
5 6
1 2 4
1 3 2
2 3 0
3 4 1
4 5 1
5 2 1
4 4
1 2 4
1 3 6
1 4 8
4 2 1000000
3 3
1 2 100
2 1 10
2 3 1000

output:

5
18
1100

result:

ok 3 number(s): "5 18 1100"

Test #2:

score: 0
Accepted
time: 45ms
memory: 3556kb

input:

50000
4 5
2 4 998973548
2 3 501271695
4 1 778395982
1 4 32454891
1 2 757288934
4 5
1 4 720856669
2 3 665098951
3 4 407461517
2 1 866914401
1 2 457859826
4 5
1 2 75288664
1 4 624893594
3 2 458973866
2 4 769074655
2 3 834773751
4 5
2 3 237060634
2 4 297307882
3 4 200383586
1 2 42856502
3 1 16574713
4 ...

output:

1291015520
1530420294
1534956009
480300722
1366795927
1541095843
2493849488
858095911
1034153425
793861088
605832428
1051598350
612891589
1265994009
517769091
1678219738
1556463491
93634961
960978736
984886788
1696503797
1002892611
1969660290
1431417780
1515267731
977157479
1937478556
654475526
1401...

result:

ok 50000 numbers

Test #3:

score: -100
Wrong Answer
time: 44ms
memory: 3836kb

input:

50000
4 6
1 3 754771977
2 3 517886121
1 4 392356144
1 2 702785740
3 4 888230940
2 1 829304957
4 6
2 4 255940037
1 2 380616616
1 4 819140865
3 4 36965607
1 3 496378345
4 3 652252309
4 6
2 4 179216787
4 2 401136502
1 2 715271531
1 3 859345710
3 4 24470489
1 4 148650889
4 6
3 2 20348069
1 2 152861663
1...

output:

1613028005
913960568
1284952701
1294564551
199037829
1236121455
983447828
1161647829
1289612543
2444304029
431872921
1272140390
949528400
2328941976
696541797
363553357
999320657
2221495861
879052116
1287531701
912524980
1072419431
1187727045
1571845059
1184110956
1136184594
430092563
1132894799
962...

result:

wrong answer 313th numbers differ - expected: '1326090611', found: '1821468187'