oj.uz

Submission #880823

# Submission time Handle Problem Language Result Execution time Memory
880823 2023-11-30T06:13:16 Z vjudge1 Love Polygon (BOI18_polygon) C++17
46 / 100
 732 ms 28752 KB 
/// I'm only brave when I have to be
#include <bits/stdc++.h>
#define F first
#define S second
#define pb push_back
#define ppb pop_back
#define fast_io ios::sync_with_stdio(false);cin.tie(NULL);
#define file_io freopen("input.txt","r",stdin);freopen("output.txt","w",stdout);
#define FOR(i,k,n) for(int i = k; i < n; ++ i)
#define debf cout<<"(0-0)\n";
#define all(x) x.begin(), x.end()
#define dec(x) cout << fixed << setprecision(x);
#define pf push_front
#define ppf pop_front
#define dash " ------- "
#define what(x) cerr << #x << " is " << x << endl;
#define eb emplace_back
//#define int short int
#define int long long
#define sz(s) (int) (s.size())
#define fl cout.flush()

using namespace std;

typedef long long ll;
typedef pair <int, int> pii;
typedef pair <int, pii> pip;
typedef pair <pii, int> ppi;
typedef pair <ll, ll> pll;
typedef unsigned long long ull;
typedef long double ld;

template <class T> using max_heap = priority_queue <T, vector <T>, less <T> >;
template <class T> using min_heap = priority_queue <T, vector <T>, greater <T> >;

constexpr int MOD = 1e9 + 7, N = 2e5 + 8, M = 1e5, SQ = 300, INF = 2e18 + 8, LGN = 21, mod = 998244353, P = 131113;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

bool mark[N], used[N];
int n, pt, sz, ans, mat[25][25], dp[(1<<LGN)];
map <string, int> m;
vector <int> adj[N];

void dfs (int u){
  mark[u] = true;
  ++ sz;
  for (int i : adj[u]){
    if (!mark[i]){
      dfs (i);
    }
  }
  return;
}

void dfs2 (int u, int par = -1){
  mark[u] = true;
  for (int i : adj[u]){
    if (!mark[i]){
      dfs2 (i, u);
    }
  }
  if (par != -1 && !used[u] && !used[par]){
    ++ ans;
    used[u] = true;
    used[par] = true;
  }
  return;
}

int32_t main(){
  fast_io;
  cin >> n;
  if (n & 1){
    cout << -1;
    return 0;
  }
  if (n <= 20){
    set <string> s;
    FOR (i, 0, n){
      string ss, tt;
      cin >> ss >> tt;
      if (s.find(ss) == s.end()){
        m[ss] = pt ++;
        s.insert(ss);
      }
      if (s.find(tt) == s.end()){
        m[tt] = pt ++;
        s.insert(tt);
      }
      mat[m[ss]][m[tt]] = 1;
      //cout << m[ss] << " " << m[tt] << '\n';
    }
    fill (dp, dp + (1 << LGN), INF);
    dp[0] = 0;
    for (int i = 1; i < (1 << n); ++ i){
      for (int j = 0; j < n; ++ j){
        if (i & (1 << j)){
          for (int k = 0; k < n; ++ k){
            if ((i & (1 << k)) && j != k){
              dp[i] = min (dp[i], dp[i^(1<<j)^(1<<k)] + 2 - mat[j][k] - mat[k][j]);
              //cout << i << " updated from " << (i^(1<<j)^(1<<k)) << " " << dp[i^(1<<j)^(1<<k)] << "  " << j << " " << k << " : " << mat[j][k] << " " << mat[k][j] << '\n';
            }
          }
        }
      }
      //cout << i << " " << dp[i] << '\n';
    }
    cout << dp[(1<<n)-1];
    return 0;
  }
  set <string> s;
  FOR (i, 0, n){
    string ss, tt;
    cin >> ss >> tt;
    s.insert(tt);
    if (m[ss] == 0){
      m[ss] = ++ pt;
    }
    if (m[tt] == 0){
      m[tt] = ++ pt;
    }
    adj[m[ss]].pb(m[tt]);
  }
  if (s.size() == n){
    for (int i = 1; i <= n; ++ i){
      if (!mark[i]){
        dfs (i);
        if (sz == 2){
          sz = 0;
          continue;
        }
        ans += (sz + 1) / 2;
        sz = 0;
      }
    }
    cout << ans;
  }
  else {
    FOR (i, 1, pt + 1){
      if (!mark[i]){
        dfs2 (i);
      }
    }
    cout << n - ans << '\n';
  }
  return 0;
}

// Yesterday is history
// Tomorrow is a mystery
// but today is a gift
// That is why it is called the present

Compilation message

polygon.cpp: In function 'int32_t main()':
polygon.cpp:125:16: warning: comparison of integer expressions of different signedness: 'std::set<std::__cxx11::basic_string<char> >::size_type' {aka 'long unsigned int'} and 'long long int' [-Wsign-compare]
  125 |   if (s.size() == n){
      |       ~~~~~~~~~^~~~

Subtask #1
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 694 ms 21560 KB Output is correct
2 Correct 691 ms 21556 KB Output is correct
3 Correct 691 ms 21560 KB Output is correct
4 Correct 4 ms 21592 KB Output is correct
5 Correct 1 ms 6748 KB Output is correct
6 Correct 1 ms 6748 KB Output is correct
7 Correct 687 ms 21556 KB Output is correct
8 Correct 690 ms 21336 KB Output is correct
9 Correct 693 ms 21564 KB Output is correct
10 Correct 689 ms 21556 KB Output is correct
11 Correct 732 ms 21560 KB Output is correct
12 Correct 4 ms 21340 KB Output is correct
13 Correct 4 ms 21340 KB Output is correct
14 Correct 4 ms 21340 KB Output is correct
15 Correct 4 ms 21584 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 21336 KB Output is correct
2 Correct 4 ms 21340 KB Output is correct
3 Correct 4 ms 21336 KB Output is correct
4 Correct 285 ms 28552 KB Output is correct
5 Correct 239 ms 25660 KB Output is correct
6 Correct 243 ms 28752 KB Output is correct
7 Correct 1 ms 6744 KB Output is correct

Subtask #3
0 / 29.0

# Verdict Execution time Memory Grader output
1 Incorrect 219 ms 23636 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 694 ms 21560 KB Output is correct
2 Correct 691 ms 21556 KB Output is correct
3 Correct 691 ms 21560 KB Output is correct
4 Correct 4 ms 21592 KB Output is correct
5 Correct 1 ms 6748 KB Output is correct
6 Correct 1 ms 6748 KB Output is correct
7 Correct 687 ms 21556 KB Output is correct
8 Correct 690 ms 21336 KB Output is correct
9 Correct 693 ms 21564 KB Output is correct
10 Correct 689 ms 21556 KB Output is correct
11 Correct 732 ms 21560 KB Output is correct
12 Correct 4 ms 21340 KB Output is correct
13 Correct 4 ms 21340 KB Output is correct
14 Correct 4 ms 21340 KB Output is correct
15 Correct 4 ms 21584 KB Output is correct
16 Correct 4 ms 21336 KB Output is correct
17 Correct 4 ms 21340 KB Output is correct
18 Correct 4 ms 21336 KB Output is correct
19 Correct 285 ms 28552 KB Output is correct
20 Correct 239 ms 25660 KB Output is correct
21 Correct 243 ms 28752 KB Output is correct
22 Correct 1 ms 6744 KB Output is correct
23 Incorrect 219 ms 23636 KB Output isn't correct
24 Halted 0 ms 0 KB -