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Submission #875874

# Submission time Handle Problem Language Result Execution time Memory
875874 2023-11-20T16:26:14 Z Kanon Simurgh (IOI17_simurgh) C++14
100 / 100
 240 ms 12204 KB 
#include <bits/stdc++.h>
#include "simurgh.h"

using namespace std;

class dsu {
 public:
  vector<int> p;
  int n;

  dsu(int _n) : n(_n) {
    p.resize(n);
    iota(p.begin(), p.end(), 0);
  }

  inline int get(int x) {
    return (x == p[x] ? x : (p[x] = get(p[x])));
  }

  inline bool unite(int x, int y) {
    x = get(x);
    y = get(y);
    if (x != y) {
      p[x] = y;
      return true;
    }
    return false;
  }
};

struct Edge {
  int from;
  int to;
  int cost;
  int id;
  Edge(){};
  Edge(int _from, int _to, int _cost, int _id) : from(_from), to(_to), cost(_cost), id(_id){};
};

struct graph {
  int n;
  vector<vector<int>> g;
  vector<Edge> ed;
  vector<bool> was;
  graph(int _n) {
    n = _n;
    g.resize(n);
    was.resize(n);
  }
  void add(int u, int v, int cost = 0) {
    g[u].push_back(ed.size());
    ed.emplace_back(u, v, cost, ed.size());
    g[v].push_back(ed.size());
    ed.emplace_back(v, u, -cost, ed.size());
  }

  void init_dfs() {
    fill(was.begin(), was.end(), false);
  }

  template<typename E, typename F, typename G>
  void _dp_dfs(int u, E&& bc, F&& fc, G&& gc) {
    was[u] = true;
    for(auto &e : g[u]) {
      int v = ed[e].to;
      if (was[v]) {
        bc(u, v, ed[e]);
        continue;
      }
      fc(u, v, ed[e]);
      _dp_dfs(v, bc, fc, gc);
      gc(u, v, ed[e]);
    }
  }

  const vector<int>& operator[](int u){
      return g[u];
  }
};

vector<int> find_roads(int n, vector<int> n1, vector<int> n2) {

  int m = n1.size();
  graph gr(n);
  for (int i = 0; i < m; i++) {
    gr.add(n1[i], n2[i]);
  }

  vector<int> cost(m, -2);
  graph edges(m);

  vector<int> par(n, -1);
  vector<int> dep(n);
  vector<int> highest(n, -1);
  gr._dp_dfs(0,
    [&](int u, int v, Edge e) {
      if (dep[v] == dep[u] - 1) {
        return;
      }
      if (highest[u] == -1 || dep[gr.ed[highest[u]].to] > dep[v]) {
        highest[u] = e.id;
      }
    },
    [&](int u, int v, Edge e) {
      par[v] = e.id ^ 1;
      dep[v] = dep[u] + 1;
    },
    [&](int u, int v, Edge e) {
      int eu = highest[u], pu = eu == -1 ? u : gr.ed[eu].to;
      int ev = highest[v], pv = ev == -1 ? v : gr.ed[ev].to;
      if (dep[pu] > dep[pv]) {
        highest[u] = ev;
      }
    }
  );

  set<int> tree;
  for (int i = 1; i < n; i++) {
    tree.insert(par[i] >> 1);
  }
  auto calc = [&](set<int> ed) {
    vector<int> que;
    for (int i : ed) que.push_back(i);
    return count_common_roads(que);
  };
  int sum = calc(tree);

  auto diff = [&](int ev, int eu) {
    tree.erase(eu);
    tree.insert(ev);
    int p = calc(tree);
    tree.erase(ev);
    tree.insert(eu);
    return p - sum;
  };

  for (int v = 1; v < n; v++) {
    int pv = par[v];
    int u = gr.ed[pv].to;
    int pu = par[u];
    int w = highest[v] != -1 ? gr.ed[highest[v]].to : v;
    if (dep[w] < dep[v]) {
      int d = diff(highest[v] >> 1, pv >> 1);
      edges.add(pv >> 1, highest[v] >> 1, d);
    }
    if (dep[w] < dep[u]) {
      int d = diff(highest[v] >> 1, pu >> 1);
      edges.add(pu >> 1, highest[v] >> 1, d);
    }
  }

  for (int e : tree) {
    if (cost[e] != -2) continue;
    if (edges[e].empty()) {
      cost[e] = 1;
    } else {
      vector<int> que = {e};
      edges._dp_dfs(e,
        [&](int u, int v, Edge E){},
        [&](int u, int v, Edge E){
          cost[v] = cost[u] + E.cost;
          que.push_back(v);
        },
        [&](int u, int v, Edge E){}
      );
      int mn = INT_MAX;
      for (int i : que) mn = min(mn, cost[i]);
      for (int i : que) {
        cost[i] -= mn;
        assert(0 <= cost[i] && cost[i] <= 1);
      }
    }
  }

  auto calc_sum = [&](vector<int> forest) {
    dsu d(n);
    for (int e : forest) {
      e <<= 1;
      int u = gr.ed[e].from, v = gr.ed[e].to;
      d.unite(u, v);
    }
    int calced = 0;
    for (int e : tree) {
      e <<= 1;
      int u = gr.ed[e].from, v = gr.ed[e].to;
      if (d.unite(u, v)) {
        calced += cost[e >> 1];
        forest.push_back(e >> 1);
      }
    }
    return count_common_roads(forest) - calced;
  };

  function<void(vector<int>, int)> solve = [&](vector<int> Eds, int Sum) {
    if (Sum == 0) {
      for (int e : Eds) {
        cost[e] = 0;
      }
      return;
    }
    if (Sum == (int) Eds.size()) {
      for (int e : Eds) {
        cost[e] = 1;
      }
      return;
    }
    int L = 0, R = Eds.size(), Mid = (L + R) >> 1;
    vector<int> Leds, Reds;
    for (int i = 0; i < (int) Eds.size(); i++) {
      if (i < Mid) Leds.push_back(Eds[i]);
      else Reds.push_back(Eds[i]);
    }
    int Lsum = calc_sum(Leds), Rsum = Sum - Lsum;
    solve(Leds, Lsum);
    solve(Reds, Rsum);
  };

  int Left = 0;
  for (int i = 0; i < m; i++) Left += cost[i] == -2;

  while (Left) {
    dsu d(n);
    vector<int> Eds;
    for (int e = 0; e < m; e++) {
      if (cost[e] != -2) continue;
      int u = gr.ed[e << 1].from, v = gr.ed[e << 1].to;
      if (d.unite(u, v)) Eds.push_back(e);
    }
    assert(Eds.size());
    solve(Eds, calc_sum(Eds));
    Left -= Eds.size();
  }

  vector<int> ret;
  for (int e = 0; e < m; e++) {
    assert(0 <= cost[e] && cost[e] <= 1);
    if (cost[e] == 1) ret.push_back(e);
  }
  return ret;

}

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB correct
2 Correct 1 ms 420 KB correct
3 Correct 1 ms 348 KB correct
4 Correct 0 ms 348 KB correct
5 Correct 0 ms 348 KB correct
6 Correct 0 ms 436 KB correct
7 Correct 0 ms 348 KB correct
8 Correct 0 ms 604 KB correct
9 Correct 1 ms 348 KB correct
10 Correct 0 ms 412 KB correct
11 Correct 0 ms 348 KB correct
12 Correct 0 ms 348 KB correct
13 Correct 0 ms 348 KB correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB correct
2 Correct 1 ms 420 KB correct
3 Correct 1 ms 348 KB correct
4 Correct 0 ms 348 KB correct
5 Correct 0 ms 348 KB correct
6 Correct 0 ms 436 KB correct
7 Correct 0 ms 348 KB correct
8 Correct 0 ms 604 KB correct
9 Correct 1 ms 348 KB correct
10 Correct 0 ms 412 KB correct
11 Correct 0 ms 348 KB correct
12 Correct 0 ms 348 KB correct
13 Correct 0 ms 348 KB correct
14 Correct 2 ms 348 KB correct
15 Correct 2 ms 568 KB correct
16 Correct 2 ms 348 KB correct
17 Correct 1 ms 348 KB correct
18 Correct 1 ms 348 KB correct
19 Correct 1 ms 444 KB correct
20 Correct 2 ms 348 KB correct
21 Correct 1 ms 348 KB correct
22 Correct 1 ms 348 KB correct
23 Correct 1 ms 348 KB correct
24 Correct 1 ms 348 KB correct
25 Correct 1 ms 600 KB correct
26 Correct 1 ms 348 KB correct
27 Correct 1 ms 348 KB correct
28 Correct 1 ms 348 KB correct
29 Correct 1 ms 348 KB correct
30 Correct 1 ms 348 KB correct
31 Correct 1 ms 348 KB correct
32 Correct 1 ms 348 KB correct
33 Correct 1 ms 348 KB correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB correct
2 Correct 1 ms 420 KB correct
3 Correct 1 ms 348 KB correct
4 Correct 0 ms 348 KB correct
5 Correct 0 ms 348 KB correct
6 Correct 0 ms 436 KB correct
7 Correct 0 ms 348 KB correct
8 Correct 0 ms 604 KB correct
9 Correct 1 ms 348 KB correct
10 Correct 0 ms 412 KB correct
11 Correct 0 ms 348 KB correct
12 Correct 0 ms 348 KB correct
13 Correct 0 ms 348 KB correct
14 Correct 2 ms 348 KB correct
15 Correct 2 ms 568 KB correct
16 Correct 2 ms 348 KB correct
17 Correct 1 ms 348 KB correct
18 Correct 1 ms 348 KB correct
19 Correct 1 ms 444 KB correct
20 Correct 2 ms 348 KB correct
21 Correct 1 ms 348 KB correct
22 Correct 1 ms 348 KB correct
23 Correct 1 ms 348 KB correct
24 Correct 1 ms 348 KB correct
25 Correct 1 ms 600 KB correct
26 Correct 1 ms 348 KB correct
27 Correct 1 ms 348 KB correct
28 Correct 1 ms 348 KB correct
29 Correct 1 ms 348 KB correct
30 Correct 1 ms 348 KB correct
31 Correct 1 ms 348 KB correct
32 Correct 1 ms 348 KB correct
33 Correct 1 ms 348 KB correct
34 Correct 39 ms 3216 KB correct
35 Correct 38 ms 3024 KB correct
36 Correct 30 ms 2340 KB correct
37 Correct 8 ms 604 KB correct
38 Correct 39 ms 3100 KB correct
39 Correct 34 ms 2768 KB correct
40 Correct 29 ms 2352 KB correct
41 Correct 42 ms 3024 KB correct
42 Correct 39 ms 3024 KB correct
43 Correct 14 ms 1824 KB correct
44 Correct 12 ms 1492 KB correct
45 Correct 12 ms 1748 KB correct
46 Correct 12 ms 1512 KB correct
47 Correct 8 ms 860 KB correct
48 Correct 4 ms 540 KB correct
49 Correct 7 ms 604 KB correct
50 Correct 10 ms 1068 KB correct
51 Correct 13 ms 1748 KB correct
52 Correct 11 ms 1492 KB correct
53 Correct 11 ms 1492 KB correct
54 Correct 14 ms 1988 KB correct
55 Correct 12 ms 1820 KB correct
56 Correct 12 ms 1748 KB correct
57 Correct 12 ms 1748 KB correct

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB correct
2 Correct 1 ms 440 KB correct
3 Correct 129 ms 8904 KB correct
4 Correct 216 ms 12204 KB correct
5 Correct 213 ms 11900 KB correct
6 Correct 231 ms 11944 KB correct
7 Correct 234 ms 11964 KB correct
8 Correct 225 ms 11948 KB correct
9 Correct 214 ms 11944 KB correct
10 Correct 208 ms 11956 KB correct
11 Correct 235 ms 11956 KB correct
12 Correct 206 ms 11932 KB correct
13 Correct 0 ms 348 KB correct
14 Correct 209 ms 11968 KB correct
15 Correct 222 ms 11964 KB correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB correct
2 Correct 1 ms 420 KB correct
3 Correct 1 ms 348 KB correct
4 Correct 0 ms 348 KB correct
5 Correct 0 ms 348 KB correct
6 Correct 0 ms 436 KB correct
7 Correct 0 ms 348 KB correct
8 Correct 0 ms 604 KB correct
9 Correct 1 ms 348 KB correct
10 Correct 0 ms 412 KB correct
11 Correct 0 ms 348 KB correct
12 Correct 0 ms 348 KB correct
13 Correct 0 ms 348 KB correct
14 Correct 2 ms 348 KB correct
15 Correct 2 ms 568 KB correct
16 Correct 2 ms 348 KB correct
17 Correct 1 ms 348 KB correct
18 Correct 1 ms 348 KB correct
19 Correct 1 ms 444 KB correct
20 Correct 2 ms 348 KB correct
21 Correct 1 ms 348 KB correct
22 Correct 1 ms 348 KB correct
23 Correct 1 ms 348 KB correct
24 Correct 1 ms 348 KB correct
25 Correct 1 ms 600 KB correct
26 Correct 1 ms 348 KB correct
27 Correct 1 ms 348 KB correct
28 Correct 1 ms 348 KB correct
29 Correct 1 ms 348 KB correct
30 Correct 1 ms 348 KB correct
31 Correct 1 ms 348 KB correct
32 Correct 1 ms 348 KB correct
33 Correct 1 ms 348 KB correct
34 Correct 39 ms 3216 KB correct
35 Correct 38 ms 3024 KB correct
36 Correct 30 ms 2340 KB correct
37 Correct 8 ms 604 KB correct
38 Correct 39 ms 3100 KB correct
39 Correct 34 ms 2768 KB correct
40 Correct 29 ms 2352 KB correct
41 Correct 42 ms 3024 KB correct
42 Correct 39 ms 3024 KB correct
43 Correct 14 ms 1824 KB correct
44 Correct 12 ms 1492 KB correct
45 Correct 12 ms 1748 KB correct
46 Correct 12 ms 1512 KB correct
47 Correct 8 ms 860 KB correct
48 Correct 4 ms 540 KB correct
49 Correct 7 ms 604 KB correct
50 Correct 10 ms 1068 KB correct
51 Correct 13 ms 1748 KB correct
52 Correct 11 ms 1492 KB correct
53 Correct 11 ms 1492 KB correct
54 Correct 14 ms 1988 KB correct
55 Correct 12 ms 1820 KB correct
56 Correct 12 ms 1748 KB correct
57 Correct 12 ms 1748 KB correct
58 Correct 0 ms 348 KB correct
59 Correct 1 ms 440 KB correct
60 Correct 129 ms 8904 KB correct
61 Correct 216 ms 12204 KB correct
62 Correct 213 ms 11900 KB correct
63 Correct 231 ms 11944 KB correct
64 Correct 234 ms 11964 KB correct
65 Correct 225 ms 11948 KB correct
66 Correct 214 ms 11944 KB correct
67 Correct 208 ms 11956 KB correct
68 Correct 235 ms 11956 KB correct
69 Correct 206 ms 11932 KB correct
70 Correct 0 ms 348 KB correct
71 Correct 209 ms 11968 KB correct
72 Correct 222 ms 11964 KB correct
73 Correct 0 ms 348 KB correct
74 Correct 209 ms 11944 KB correct
75 Correct 234 ms 11792 KB correct
76 Correct 81 ms 4556 KB correct
77 Correct 224 ms 11876 KB correct
78 Correct 240 ms 11928 KB correct
79 Correct 236 ms 11712 KB correct
80 Correct 203 ms 11456 KB correct
81 Correct 180 ms 10380 KB correct
82 Correct 230 ms 11720 KB correct
83 Correct 127 ms 6368 KB correct
84 Correct 85 ms 8140 KB correct
85 Correct 73 ms 6808 KB correct
86 Correct 53 ms 4760 KB correct
87 Correct 41 ms 3620 KB correct
88 Correct 34 ms 2776 KB correct
89 Correct 32 ms 2768 KB correct
90 Correct 30 ms 2256 KB correct
91 Correct 19 ms 856 KB correct
92 Correct 19 ms 604 KB correct
93 Correct 80 ms 6764 KB correct
94 Correct 51 ms 4812 KB correct
95 Correct 47 ms 4556 KB correct
96 Correct 45 ms 2512 KB correct
97 Correct 33 ms 2768 KB correct
98 Correct 37 ms 3652 KB correct
99 Correct 34 ms 2768 KB correct
100 Correct 32 ms 1084 KB correct
101 Correct 23 ms 688 KB correct
102 Correct 62 ms 6092 KB correct
103 Correct 62 ms 6276 KB correct
104 Correct 61 ms 6248 KB correct
105 Correct 67 ms 6196 KB correct