oj.uz

Submission #854932

# Submission time Handle Problem Language Result Execution time Memory
854932 2023-09-29T12:17:22 Z JustInCase Bridges (APIO19_bridges) C++17
100 / 100
 1682 ms 13180 KB 
#include <algorithm>
#include <cassert>
#include <iostream>
#include <stack>
#include <vector>

using namespace std;

const int BLOCK_SIZE = 1000;

struct edge {
  int u, v, w;

  static bool compDecrW(edge &e1, edge &e2) { return e1.w > e2.w; }
};

struct update {
  int e, w;
};

struct query {
  int id;
  int v, w;

  static bool compDecrW(query &q1, query &q2) { return q1.w > q2.w; }
};

struct rollback_dsu {
  struct change {
    int oldRoot, newRoot;
  };

  vector<int> parent;
  vector<int> compSize;
  stack<change> changes;

  rollback_dsu(int cntNodes) {
    parent.resize(cntNodes);
    compSize.resize(cntNodes, 1);

    for (int i = 0; i < cntNodes; i++) {
      parent[i] = i;
    }
  }

  int findRoot(int x) {
    while (parent[x] != x)
      x = parent[x];
    return x;
  }

  void unite(int x, int y) {
    int rootX = findRoot(x);
    int rootY = findRoot(y);

    if (rootX == rootY)
      return;

    if (compSize[rootX] <= compSize[rootY]) {
      parent[rootX] = rootY;
      compSize[rootY] += compSize[rootX];
      changes.push(change{rootX, rootY});
    } else {
      parent[rootY] = rootX;
      compSize[rootX] += compSize[rootY];
      changes.push(change{rootY, rootX});
    }
  }

  void markAsStable() {
    while (!changes.empty())
      changes.pop();
  }

  void rollbackToStable() {
    while (!changes.empty()) {
      auto [oldRoot, newRoot] = changes.top();
      changes.pop();

      parent[oldRoot] = oldRoot;
      compSize[newRoot] -= compSize[oldRoot];
    }
  }
};

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

  int n, m;
  cin >> n >> m;

  vector<edge> edges(m);
  for (int i = 0; i < m; i++) {
    int u, v, w;
    cin >> u >> v >> w;

    u--;
    v--;

    edges[i] = edge{u, v, w};
  }

  int q;
  cin >> q;

  vector<bool> changed(m, false);
  for (int i = 0; i < q; i += BLOCK_SIZE) {
    vector<int> t(min(BLOCK_SIZE, q - i));
    vector<update> updates;
    vector<query> queries;

    fill(changed.begin(), changed.end(), false);

    for (int j = 0; j < min(BLOCK_SIZE, q - i); j++) {
      cin >> t[j];

      if (t[j] == 1) {
        int e, w;
        cin >> e >> w;

        e--;

        updates.push_back(update{e, w});
        changed[e] = true;
      } else {
        int v, w;
        cin >> v >> w;

        v--;

        queries.push_back(query{(int)queries.size(), v, w});
      }
    }

    vector<vector<edge>> additionalEdges(queries.size());
    int queryInd = 0, updateInd = 0;
    for (int j = 0; j < min(BLOCK_SIZE, q - i); j++) {
      if (t[j] == 1) {
        edges[updates[updateInd].e].w = updates[updateInd].w;
        updateInd++;
      } else {
        assert(queryInd < queries.size());
        for (auto u : updates) {
          if (edges[u.e].w >= queries[queryInd].w)
            additionalEdges[queryInd].push_back(edges[u.e]);
        }
        queryInd++;
      }
    }

    vector<edge> unchanged;
    for (int j = 0; j < m; j++) {
      if (!changed[j])
        unchanged.push_back(edges[j]);
    }

    sort(unchanged.begin(), unchanged.end(), edge::compDecrW);
    sort(queries.begin(), queries.end(), query::compDecrW);

    auto dsu = rollback_dsu(n);

    int edgePtr = 0;
    vector<int> ans(queries.size());
    for (int j = 0; j < queries.size(); j++) {
      while (edgePtr < unchanged.size() &&
             unchanged[edgePtr].w >= queries[j].w) {
        dsu.unite(unchanged[edgePtr].u, unchanged[edgePtr].v);
        edgePtr++;
      }

      dsu.markAsStable();

      for (auto e : additionalEdges[queries[j].id]) {
        dsu.unite(e.u, e.v);
      }

      assert(queries[j].id >= 0 && queries[j].id < ans.size());
      ans[queries[j].id] = dsu.compSize[dsu.findRoot(queries[j].v)];

      dsu.rollbackToStable();
    }

    for (auto x : ans) {
      cout << x << endl;
    }
  }
}

Compilation message

In file included from /usr/include/c++/10/cassert:44,
                 from bridges.cpp:2:
bridges.cpp: In function 'int main()':
bridges.cpp:143:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<query>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  143 |         assert(queryInd < queries.size());
      |                ~~~~~~~~~^~~~~~~~~~~~~~~~
bridges.cpp:165:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<query>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  165 |     for (int j = 0; j < queries.size(); j++) {
      |                     ~~^~~~~~~~~~~~~~~~
bridges.cpp:166:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<edge>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  166 |       while (edgePtr < unchanged.size() &&
      |              ~~~~~~~~^~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/10/cassert:44,
                 from bridges.cpp:2:
bridges.cpp:178:50: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  178 |       assert(queries[j].id >= 0 && queries[j].id < ans.size());

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 600 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 31 ms 2556 KB Output is correct
4 Correct 13 ms 344 KB Output is correct
5 Correct 31 ms 3176 KB Output is correct
6 Correct 28 ms 3416 KB Output is correct
7 Correct 32 ms 4004 KB Output is correct
8 Correct 33 ms 2372 KB Output is correct
9 Correct 37 ms 5200 KB Output is correct
10 Correct 33 ms 2648 KB Output is correct
11 Correct 35 ms 2460 KB Output is correct
12 Correct 43 ms 3264 KB Output is correct
13 Correct 37 ms 2908 KB Output is correct
14 Correct 37 ms 2476 KB Output is correct
15 Correct 42 ms 2716 KB Output is correct
16 Correct 35 ms 4160 KB Output is correct
17 Correct 40 ms 3680 KB Output is correct

Subtask #2
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 996 ms 4952 KB Output is correct
2 Correct 984 ms 4828 KB Output is correct
3 Correct 988 ms 4912 KB Output is correct
4 Correct 991 ms 4892 KB Output is correct
5 Correct 977 ms 4836 KB Output is correct
6 Correct 1174 ms 8864 KB Output is correct
7 Correct 1086 ms 8744 KB Output is correct
8 Correct 1105 ms 8724 KB Output is correct
9 Correct 132 ms 864 KB Output is correct
10 Correct 633 ms 7024 KB Output is correct
11 Correct 619 ms 6124 KB Output is correct
12 Correct 869 ms 5176 KB Output is correct
13 Correct 766 ms 3988 KB Output is correct

Subtask #3
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 754 ms 3952 KB Output is correct
2 Correct 489 ms 4904 KB Output is correct
3 Correct 804 ms 5952 KB Output is correct
4 Correct 743 ms 4168 KB Output is correct
5 Correct 128 ms 520 KB Output is correct
6 Correct 763 ms 4952 KB Output is correct
7 Correct 699 ms 3848 KB Output is correct
8 Correct 653 ms 3208 KB Output is correct
9 Correct 584 ms 3516 KB Output is correct
10 Correct 583 ms 3072 KB Output is correct
11 Correct 528 ms 3288 KB Output is correct
12 Correct 487 ms 2480 KB Output is correct

Subtask #4
14.0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 1374 ms 5284 KB Output is correct
2 Correct 131 ms 1796 KB Output is correct
3 Correct 147 ms 6272 KB Output is correct
4 Correct 81 ms 6220 KB Output is correct
5 Correct 758 ms 7096 KB Output is correct
6 Correct 1305 ms 8760 KB Output is correct
7 Correct 758 ms 7184 KB Output is correct
8 Correct 733 ms 5580 KB Output is correct
9 Correct 715 ms 5452 KB Output is correct
10 Correct 695 ms 5744 KB Output is correct
11 Correct 1096 ms 7268 KB Output is correct
12 Correct 1055 ms 7552 KB Output is correct
13 Correct 1041 ms 7772 KB Output is correct
14 Correct 722 ms 7292 KB Output is correct
15 Correct 760 ms 7248 KB Output is correct
16 Correct 1408 ms 8500 KB Output is correct
17 Correct 1375 ms 8600 KB Output is correct
18 Correct 1394 ms 8676 KB Output is correct
19 Correct 1366 ms 8724 KB Output is correct
20 Correct 1171 ms 8268 KB Output is correct
21 Correct 1167 ms 8516 KB Output is correct
22 Correct 1308 ms 8764 KB Output is correct
23 Correct 808 ms 6768 KB Output is correct

Subtask #5
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 996 ms 4952 KB Output is correct
2 Correct 984 ms 4828 KB Output is correct
3 Correct 988 ms 4912 KB Output is correct
4 Correct 991 ms 4892 KB Output is correct
5 Correct 977 ms 4836 KB Output is correct
6 Correct 1174 ms 8864 KB Output is correct
7 Correct 1086 ms 8744 KB Output is correct
8 Correct 1105 ms 8724 KB Output is correct
9 Correct 132 ms 864 KB Output is correct
10 Correct 633 ms 7024 KB Output is correct
11 Correct 619 ms 6124 KB Output is correct
12 Correct 869 ms 5176 KB Output is correct
13 Correct 766 ms 3988 KB Output is correct
14 Correct 754 ms 3952 KB Output is correct
15 Correct 489 ms 4904 KB Output is correct
16 Correct 804 ms 5952 KB Output is correct
17 Correct 743 ms 4168 KB Output is correct
18 Correct 128 ms 520 KB Output is correct
19 Correct 763 ms 4952 KB Output is correct
20 Correct 699 ms 3848 KB Output is correct
21 Correct 653 ms 3208 KB Output is correct
22 Correct 584 ms 3516 KB Output is correct
23 Correct 583 ms 3072 KB Output is correct
24 Correct 528 ms 3288 KB Output is correct
25 Correct 487 ms 2480 KB Output is correct
26 Correct 999 ms 4720 KB Output is correct
27 Correct 1042 ms 6508 KB Output is correct
28 Correct 1012 ms 4832 KB Output is correct
29 Correct 762 ms 3416 KB Output is correct
30 Correct 1029 ms 5812 KB Output is correct
31 Correct 1049 ms 5948 KB Output is correct
32 Correct 1044 ms 5756 KB Output is correct
33 Correct 967 ms 4872 KB Output is correct
34 Correct 973 ms 4616 KB Output is correct
35 Correct 995 ms 4660 KB Output is correct
36 Correct 799 ms 3720 KB Output is correct
37 Correct 791 ms 3956 KB Output is correct
38 Correct 799 ms 3684 KB Output is correct
39 Correct 740 ms 3268 KB Output is correct
40 Correct 744 ms 3044 KB Output is correct
41 Correct 735 ms 3576 KB Output is correct
42 Correct 663 ms 3212 KB Output is correct
43 Correct 657 ms 2952 KB Output is correct
44 Correct 626 ms 3244 KB Output is correct

Subtask #6
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 600 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 31 ms 2556 KB Output is correct
4 Correct 13 ms 344 KB Output is correct
5 Correct 31 ms 3176 KB Output is correct
6 Correct 28 ms 3416 KB Output is correct
7 Correct 32 ms 4004 KB Output is correct
8 Correct 33 ms 2372 KB Output is correct
9 Correct 37 ms 5200 KB Output is correct
10 Correct 33 ms 2648 KB Output is correct
11 Correct 35 ms 2460 KB Output is correct
12 Correct 43 ms 3264 KB Output is correct
13 Correct 37 ms 2908 KB Output is correct
14 Correct 37 ms 2476 KB Output is correct
15 Correct 42 ms 2716 KB Output is correct
16 Correct 35 ms 4160 KB Output is correct
17 Correct 40 ms 3680 KB Output is correct
18 Correct 996 ms 4952 KB Output is correct
19 Correct 984 ms 4828 KB Output is correct
20 Correct 988 ms 4912 KB Output is correct
21 Correct 991 ms 4892 KB Output is correct
22 Correct 977 ms 4836 KB Output is correct
23 Correct 1174 ms 8864 KB Output is correct
24 Correct 1086 ms 8744 KB Output is correct
25 Correct 1105 ms 8724 KB Output is correct
26 Correct 132 ms 864 KB Output is correct
27 Correct 633 ms 7024 KB Output is correct
28 Correct 619 ms 6124 KB Output is correct
29 Correct 869 ms 5176 KB Output is correct
30 Correct 766 ms 3988 KB Output is correct
31 Correct 754 ms 3952 KB Output is correct
32 Correct 489 ms 4904 KB Output is correct
33 Correct 804 ms 5952 KB Output is correct
34 Correct 743 ms 4168 KB Output is correct
35 Correct 128 ms 520 KB Output is correct
36 Correct 763 ms 4952 KB Output is correct
37 Correct 699 ms 3848 KB Output is correct
38 Correct 653 ms 3208 KB Output is correct
39 Correct 584 ms 3516 KB Output is correct
40 Correct 583 ms 3072 KB Output is correct
41 Correct 528 ms 3288 KB Output is correct
42 Correct 487 ms 2480 KB Output is correct
43 Correct 1374 ms 5284 KB Output is correct
44 Correct 131 ms 1796 KB Output is correct
45 Correct 147 ms 6272 KB Output is correct
46 Correct 81 ms 6220 KB Output is correct
47 Correct 758 ms 7096 KB Output is correct
48 Correct 1305 ms 8760 KB Output is correct
49 Correct 758 ms 7184 KB Output is correct
50 Correct 733 ms 5580 KB Output is correct
51 Correct 715 ms 5452 KB Output is correct
52 Correct 695 ms 5744 KB Output is correct
53 Correct 1096 ms 7268 KB Output is correct
54 Correct 1055 ms 7552 KB Output is correct
55 Correct 1041 ms 7772 KB Output is correct
56 Correct 722 ms 7292 KB Output is correct
57 Correct 760 ms 7248 KB Output is correct
58 Correct 1408 ms 8500 KB Output is correct
59 Correct 1375 ms 8600 KB Output is correct
60 Correct 1394 ms 8676 KB Output is correct
61 Correct 1366 ms 8724 KB Output is correct
62 Correct 1171 ms 8268 KB Output is correct
63 Correct 1167 ms 8516 KB Output is correct
64 Correct 1308 ms 8764 KB Output is correct
65 Correct 808 ms 6768 KB Output is correct
66 Correct 999 ms 4720 KB Output is correct
67 Correct 1042 ms 6508 KB Output is correct
68 Correct 1012 ms 4832 KB Output is correct
69 Correct 762 ms 3416 KB Output is correct
70 Correct 1029 ms 5812 KB Output is correct
71 Correct 1049 ms 5948 KB Output is correct
72 Correct 1044 ms 5756 KB Output is correct
73 Correct 967 ms 4872 KB Output is correct
74 Correct 973 ms 4616 KB Output is correct
75 Correct 995 ms 4660 KB Output is correct
76 Correct 799 ms 3720 KB Output is correct
77 Correct 791 ms 3956 KB Output is correct
78 Correct 799 ms 3684 KB Output is correct
79 Correct 740 ms 3268 KB Output is correct
80 Correct 744 ms 3044 KB Output is correct
81 Correct 735 ms 3576 KB Output is correct
82 Correct 663 ms 3212 KB Output is correct
83 Correct 657 ms 2952 KB Output is correct
84 Correct 626 ms 3244 KB Output is correct
85 Correct 1593 ms 10668 KB Output is correct
86 Correct 162 ms 8240 KB Output is correct
87 Correct 103 ms 11416 KB Output is correct
88 Correct 958 ms 10012 KB Output is correct
89 Correct 1657 ms 10780 KB Output is correct
90 Correct 988 ms 10104 KB Output is correct
91 Correct 1016 ms 7612 KB Output is correct
92 Correct 1010 ms 7392 KB Output is correct
93 Correct 1132 ms 9776 KB Output is correct
94 Correct 1331 ms 9660 KB Output is correct
95 Correct 1334 ms 9352 KB Output is correct
96 Correct 1331 ms 11368 KB Output is correct
97 Correct 860 ms 8776 KB Output is correct
98 Correct 777 ms 7996 KB Output is correct
99 Correct 1611 ms 10452 KB Output is correct
100 Correct 1612 ms 10556 KB Output is correct
101 Correct 1657 ms 10528 KB Output is correct
102 Correct 1682 ms 10372 KB Output is correct
103 Correct 1475 ms 12964 KB Output is correct
104 Correct 1463 ms 13180 KB Output is correct
105 Correct 1157 ms 9856 KB Output is correct
106 Correct 1014 ms 8792 KB Output is correct
107 Correct 1235 ms 9564 KB Output is correct
108 Correct 1470 ms 11812 KB Output is correct
109 Correct 981 ms 10416 KB Output is correct