oj.uz

Submission #283254

# Submission time Handle Problem Language Result Execution time Memory
283254 2020-08-25T12:26:47 Z AlexLuchianov Love Polygon (BOI18_polygon) C++14
100 / 100
 293 ms 25044 KB 
#include <iostream>
#include <vector>
#include <cassert>
#include <cmath>
#include <map>

using ll = long long;
#define MIN(a, b) (((a) < (b)) ? (a) : (b))
#define MAX(a, b) (((a) < (b)) ? (b) : (a))
std::map<std::string, int> mp;

int const nmax = 200000;
int v[1 + nmax], used[1 + nmax];
std::vector<int> g[1 + nmax];
int frec[1 + nmax];
int dp[1 + nmax][2];

void dfs(int node) {
  used[node] = 1;
  for(int h = 0; h < g[node].size(); h++) {
    int to = g[node][h];
    if(0 == frec[to]) {
      dfs(to);
      int a = dp[node][0] + std::max(dp[to][0], dp[to][1]);
      int b = std::max(dp[node][1] + std::max(dp[to][1], dp[to][0]), dp[node][0] + dp[to][0] + 1);
      dp[node][0] = a;
      dp[node][1] = b;
    }
  }
}

int quick(std::vector<int> path) {
  std::vector<std::pair<int,int>> dp2;
  int n = path.size();
  dp2.resize(n);
  int coef = 1;
  if(path.size() == 2)
    coef = 2;
  for(int i = 0; i < path.size(); i++) {
    int node = path[i];
    if(i == 0) {
      dp2[i].first = dp[node][0];
      dp2[i].second = dp[node][1];
    } else {
      dp2[i].first = std::max(dp2[i - 1].first, dp2[i - 1].second) + dp[node][0];
      dp2[i].second = std::max(std::max(dp2[i - 1].first, dp2[i - 1].second) + dp[node][1],
                               dp2[i - 1].first + dp[node][0] + coef);
    }
  }
  return std::max(dp2[n - 1].first, dp2[n - 1].second);
}

int solve(int node) {
  std::vector<int> path;
  while(frec[node] == 0) {
    path.push_back(node);
    frec[node] = path.size();
    node = v[node];
  }
  std::vector<int> realpath;
  for(int i = 0; i < frec[node] - 1; i++)
    frec[path[i]] = 0;
  for(int i = frec[node] - 1; i < path.size(); i++)
    realpath.push_back(path[i]);
  for(int i = 0; i < realpath.size(); i++)
    dfs(realpath[i]);

  int result = quick(realpath);
  realpath.push_back(realpath[0]);
  realpath.erase(realpath.begin());
  return std::max(result, quick(realpath));
}


int main() {
  std::ios::sync_with_stdio(0);
  std::cin.tie(0);

  int n;
  std::cin >> n;
  if(n % 2 == 1) {
    std::cout << -1;
    return 0;
  }
  int ptr = 0;
  for(int i = 1;i <= n; i++) {
    std::string s, s2;
    std::cin >> s >> s2;
    if(0 == mp[s])
      mp[s] = ++ptr;
    if(0 == mp[s2])
      mp[s2] = ++ptr;
    v[mp[s]] = mp[s2];
  }
  int result = 0;
  for(int i = 1;i <= n; i++) {
    if(v[i] != i)
      g[v[i]].push_back(i);
  }
  for(int i = 1;i <= n; i++)
    if(used[i] == 0)
      result += solve(i);
  std::cout << n - result;
  return 0;
}

Compilation message

polygon.cpp: In function 'void dfs(int)':
polygon.cpp:20:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |   for(int h = 0; h < g[node].size(); h++) {
      |                  ~~^~~~~~~~~~~~~~~~
polygon.cpp: In function 'int quick(std::vector<int>)':
polygon.cpp:39:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |   for(int i = 0; i < path.size(); i++) {
      |                  ~~^~~~~~~~~~~~~
polygon.cpp: In function 'int solve(int)':
polygon.cpp:63:33: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   63 |   for(int i = frec[node] - 1; i < path.size(); i++)
      |                               ~~^~~~~~~~~~~~~
polygon.cpp:65:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   65 |   for(int i = 0; i < realpath.size(); i++)
      |                  ~~^~~~~~~~~~~~~~~~~

Subtask #1
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 4992 KB Output is correct
2 Correct 4 ms 4992 KB Output is correct
3 Correct 4 ms 4992 KB Output is correct
4 Correct 3 ms 4992 KB Output is correct
5 Correct 4 ms 4992 KB Output is correct
6 Correct 3 ms 4992 KB Output is correct
7 Correct 3 ms 4992 KB Output is correct
8 Correct 4 ms 4992 KB Output is correct
9 Correct 4 ms 4992 KB Output is correct
10 Correct 3 ms 4992 KB Output is correct
11 Correct 4 ms 4992 KB Output is correct
12 Correct 4 ms 4992 KB Output is correct
13 Correct 4 ms 4992 KB Output is correct
14 Correct 3 ms 4992 KB Output is correct
15 Correct 4 ms 4992 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 4992 KB Output is correct
2 Correct 3 ms 4992 KB Output is correct
3 Correct 3 ms 4992 KB Output is correct
4 Correct 268 ms 19320 KB Output is correct
5 Correct 271 ms 17352 KB Output is correct
6 Correct 268 ms 19648 KB Output is correct
7 Correct 4 ms 4992 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 264 ms 17496 KB Output is correct
2 Correct 288 ms 19192 KB Output is correct
3 Correct 237 ms 14584 KB Output is correct
4 Correct 4 ms 5120 KB Output is correct
5 Correct 278 ms 23160 KB Output is correct
6 Correct 264 ms 16760 KB Output is correct
7 Correct 256 ms 16888 KB Output is correct
8 Correct 272 ms 16504 KB Output is correct
9 Correct 244 ms 16120 KB Output is correct
10 Correct 223 ms 14836 KB Output is correct
11 Correct 4 ms 4992 KB Output is correct
12 Correct 3 ms 4992 KB Output is correct
13 Correct 4 ms 4992 KB Output is correct
14 Correct 4 ms 4992 KB Output is correct

Subtask #4
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 4992 KB Output is correct
2 Correct 4 ms 4992 KB Output is correct
3 Correct 4 ms 4992 KB Output is correct
4 Correct 3 ms 4992 KB Output is correct
5 Correct 4 ms 4992 KB Output is correct
6 Correct 3 ms 4992 KB Output is correct
7 Correct 3 ms 4992 KB Output is correct
8 Correct 4 ms 4992 KB Output is correct
9 Correct 4 ms 4992 KB Output is correct
10 Correct 3 ms 4992 KB Output is correct
11 Correct 4 ms 4992 KB Output is correct
12 Correct 4 ms 4992 KB Output is correct
13 Correct 4 ms 4992 KB Output is correct
14 Correct 3 ms 4992 KB Output is correct
15 Correct 4 ms 4992 KB Output is correct
16 Correct 4 ms 4992 KB Output is correct
17 Correct 3 ms 4992 KB Output is correct
18 Correct 3 ms 4992 KB Output is correct
19 Correct 268 ms 19320 KB Output is correct
20 Correct 271 ms 17352 KB Output is correct
21 Correct 268 ms 19648 KB Output is correct
22 Correct 4 ms 4992 KB Output is correct
23 Correct 264 ms 17496 KB Output is correct
24 Correct 288 ms 19192 KB Output is correct
25 Correct 237 ms 14584 KB Output is correct
26 Correct 4 ms 5120 KB Output is correct
27 Correct 278 ms 23160 KB Output is correct
28 Correct 264 ms 16760 KB Output is correct
29 Correct 256 ms 16888 KB Output is correct
30 Correct 272 ms 16504 KB Output is correct
31 Correct 244 ms 16120 KB Output is correct
32 Correct 223 ms 14836 KB Output is correct
33 Correct 4 ms 4992 KB Output is correct
34 Correct 3 ms 4992 KB Output is correct
35 Correct 4 ms 4992 KB Output is correct
36 Correct 4 ms 4992 KB Output is correct
37 Correct 293 ms 19812 KB Output is correct
38 Correct 274 ms 19172 KB Output is correct
39 Correct 276 ms 18680 KB Output is correct
40 Correct 266 ms 18424 KB Output is correct
41 Correct 256 ms 18428 KB Output is correct
42 Correct 263 ms 19064 KB Output is correct
43 Correct 268 ms 19192 KB Output is correct
44 Correct 264 ms 19064 KB Output is correct
45 Correct 270 ms 19028 KB Output is correct
46 Correct 274 ms 18940 KB Output is correct
47 Correct 250 ms 17928 KB Output is correct
48 Correct 273 ms 19320 KB Output is correct
49 Correct 287 ms 20896 KB Output is correct
50 Correct 243 ms 16240 KB Output is correct
51 Correct 4 ms 5120 KB Output is correct
52 Correct 270 ms 25044 KB Output is correct
53 Correct 256 ms 18204 KB Output is correct
54 Correct 268 ms 18680 KB Output is correct
55 Correct 253 ms 18296 KB Output is correct
56 Correct 256 ms 17784 KB Output is correct
57 Correct 195 ms 16372 KB Output is correct
58 Correct 4 ms 4992 KB Output is correct
59 Correct 4 ms 4992 KB Output is correct
60 Correct 3 ms 4992 KB Output is correct
61 Correct 3 ms 4992 KB Output is correct
62 Correct 4 ms 4992 KB Output is correct
63 Correct 4 ms 4992 KB Output is correct
64 Correct 4 ms 4992 KB Output is correct
65 Correct 290 ms 21248 KB Output is correct
66 Correct 275 ms 19320 KB Output is correct
67 Correct 273 ms 21620 KB Output is correct
68 Correct 4 ms 5120 KB Output is correct
69 Correct 3 ms 5120 KB Output is correct
70 Correct 3 ms 4992 KB Output is correct
71 Correct 3 ms 4992 KB Output is correct
72 Correct 4 ms 4992 KB Output is correct
73 Correct 4 ms 5024 KB Output is correct
74 Correct 3 ms 4992 KB Output is correct
75 Correct 3 ms 4992 KB Output is correct
76 Correct 4 ms 4992 KB Output is correct
77 Correct 3 ms 4992 KB Output is correct
78 Correct 3 ms 4992 KB Output is correct
79 Correct 4 ms 4992 KB Output is correct
80 Correct 3 ms 4992 KB Output is correct
81 Correct 3 ms 4992 KB Output is correct
82 Correct 3 ms 4992 KB Output is correct
83 Correct 4 ms 4992 KB Output is correct