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Submission #485464

# Submission time Handle Problem Language Result Execution time Memory
485464 2021-11-07T23:45:31 Z sam571128 Love Polygon (BOI18_polygon) C++17
21 / 100
 788 ms 21292 KB 
#include <bits/stdc++.h>

#define int long long
#define fastio ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

using namespace std;

const int N = 1e5+5;
int visited[N], arr[N], sz[N];
vector<int> adj[N];

void dfs(int u){
    sz[u] = 1;
    visited[u] = 1;
    for(auto v : adj[u]){
        if(visited[v]) continue;
        dfs(v);
        sz[u] += sz[v];
    }
}

int idx;
map<string,int> m;

int assign(string x){
    if(m.find(x)==m.end()){
        m[x] = idx++;
    }
    return m[x];
}

signed main(){
    fastio
    int n;
    cin >> n;

    for(int i = 0;i < n;i++){
        string a,b;
        cin >> a >> b;
        int x = assign(a);
        int y = assign(b);
        arr[x] = y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }

    if(n%2){
        cout << -1 << "\n";
        return 0;
    }

    if(n <= 20){
        int dp[1<<n];
        fill(dp,dp+(1<<n),1e18);
        dp[0] = 0;

        for(int mask = 0;mask < (1<<n); mask++){
            for(int i = 0;i < n;i++){
                if(mask&(1<<i)) continue;
                for(int j = 0;j < n;j++){
                    if(i==j||mask&(1<<j)) continue;
                    dp[mask|(1<<i)|(1<<j)] = min(dp[mask]+(arr[i]!=j)+(arr[j]!=i),dp[mask|(1<<i)|(1<<j)]);
                }
            }
        }

        cout << dp[(1<<n)-1] << "\n";
    }else{
        int ans = -1;
        for(int i = 0; i < n; i++){
            if(!visited[i]){
                ans++;
                dfs(i); 
                if(sz[i]!=2){
                    ans += sz[i]/2; 
                }else{
                    ans--;
                }

            }
        }
        cout << max(ans,(int)0) << "\n";
    }
}

Subtask #1
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 788 ms 10860 KB Output is correct
2 Correct 728 ms 10856 KB Output is correct
3 Correct 700 ms 10864 KB Output is correct
4 Correct 2 ms 2636 KB Output is correct
5 Correct 2 ms 2636 KB Output is correct
6 Correct 2 ms 2636 KB Output is correct
7 Correct 715 ms 10860 KB Output is correct
8 Correct 747 ms 10860 KB Output is correct
9 Correct 736 ms 10860 KB Output is correct
10 Correct 724 ms 10860 KB Output is correct
11 Correct 711 ms 10948 KB Output is correct
12 Correct 1 ms 2636 KB Output is correct
13 Correct 1 ms 2636 KB Output is correct
14 Correct 2 ms 2636 KB Output is correct
15 Correct 2 ms 2636 KB Output is correct

Subtask #2
0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2636 KB Output is correct
2 Correct 1 ms 2636 KB Output is correct
3 Correct 1 ms 2636 KB Output is correct
4 Incorrect 220 ms 21292 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #3
0 / 29.0

# Verdict Execution time Memory Grader output
1 Incorrect 222 ms 16352 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 788 ms 10860 KB Output is correct
2 Correct 728 ms 10856 KB Output is correct
3 Correct 700 ms 10864 KB Output is correct
4 Correct 2 ms 2636 KB Output is correct
5 Correct 2 ms 2636 KB Output is correct
6 Correct 2 ms 2636 KB Output is correct
7 Correct 715 ms 10860 KB Output is correct
8 Correct 747 ms 10860 KB Output is correct
9 Correct 736 ms 10860 KB Output is correct
10 Correct 724 ms 10860 KB Output is correct
11 Correct 711 ms 10948 KB Output is correct
12 Correct 1 ms 2636 KB Output is correct
13 Correct 1 ms 2636 KB Output is correct
14 Correct 2 ms 2636 KB Output is correct
15 Correct 2 ms 2636 KB Output is correct
16 Correct 1 ms 2636 KB Output is correct
17 Correct 1 ms 2636 KB Output is correct
18 Correct 1 ms 2636 KB Output is correct
19 Incorrect 220 ms 21292 KB Output isn't correct
20 Halted 0 ms 0 KB -