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Submission #924367

# Submission time Handle Problem Language Result Execution time Memory
924367 2024-02-08T23:52:41 Z aykhn Love Polygon (BOI18_polygon) C++17
29 / 100
 155 ms 24400 KB 
#include <bits/stdc++.h>
// author: aykhn
using namespace std;
#define int long long
#define inf 0x3F3F3F3F
 
const int MXN = 1e5 + 5;
 
int n;
vector<int> adj[MXN];
map<string, int> mp;
int to[MXN], dp[MXN][2];
 
void dfs(int a)
{
    if (adj[a].empty())
    {
        dp[a][0] = dp[a][1] = 1;
        return;
    }
    dp[a][0] = 0;
    dp[a][1] = inf;
    for (int v : adj[a])
    {
        dfs(v);
        dp[a][0] += min(dp[v][0], dp[v][1]);
    }
    for (int v : adj[a])
    {
        dp[a][1] = min(dp[a][1], dp[a][0] - min(dp[v][0], dp[v][1]) + dp[v][0] - 1);
    }
    dp[a][0]++;
    assert(dp[a][1] <= dp[a][0]);
}
 
signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(nullptr);
    int n, m = 0;
    cin >> n;
    if (n & 1)
    {
        cout << -1 << '\n';
        return 0;
    }
    for (int i = 1; i <= n; i++)
    {
        string a, b;
        cin >> a >> b;
        if (mp.find(a) == mp.end()) mp[a] = ++m;
        if (mp.find(b) == mp.end()) mp[b] = ++m;
        to[mp[a]] = mp[b];
    }
    vector<int> r;
    for (int i = 1; i <= m; i++)
    {
        if (to[i] == i) r.push_back(i);
        if (to[to[i]] == i) continue;
        adj[to[i]].push_back(i);
    }
    int res = 0;
    for (int i : r)
    {
        dfs(i);
        res += min(dp[i][0], dp[i][1]);
    }
    cout << (n + res)/2 << '\n';
}

Subtask #1
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4956 KB Output is correct
2 Correct 2 ms 4952 KB Output is correct
3 Correct 1 ms 4952 KB Output is correct
4 Correct 2 ms 4956 KB Output is correct
5 Correct 1 ms 2908 KB Output is correct
6 Correct 1 ms 3160 KB Output is correct
7 Incorrect 1 ms 4956 KB Output isn't correct
8 Halted 0 ms 0 KB -

Subtask #2
0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4956 KB Output is correct
2 Incorrect 1 ms 4956 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 148 ms 15344 KB Output is correct
2 Correct 153 ms 18632 KB Output is correct
3 Correct 132 ms 15428 KB Output is correct
4 Correct 1 ms 2904 KB Output is correct
5 Correct 155 ms 24400 KB Output is correct
6 Correct 147 ms 15952 KB Output is correct
7 Correct 151 ms 15956 KB Output is correct
8 Correct 130 ms 15820 KB Output is correct
9 Correct 140 ms 15704 KB Output is correct
10 Correct 113 ms 15240 KB Output is correct
11 Correct 1 ms 4952 KB Output is correct
12 Correct 1 ms 4956 KB Output is correct
13 Correct 1 ms 4952 KB Output is correct
14 Correct 2 ms 4956 KB Output is correct

Subtask #4
0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4956 KB Output is correct
2 Correct 2 ms 4952 KB Output is correct
3 Correct 1 ms 4952 KB Output is correct
4 Correct 2 ms 4956 KB Output is correct
5 Correct 1 ms 2908 KB Output is correct
6 Correct 1 ms 3160 KB Output is correct
7 Incorrect 1 ms 4956 KB Output isn't correct
8 Halted 0 ms 0 KB -