Submission #645155

#	Time	Username	Problem	Language	Result	Execution time	Memory
645155		mychecksedad	Love Polygon (BOI18_polygon)	C++17	21 / 100	273 ms	11280 KiB

polygon

/* Author : Mychecksdead */
#include<bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef long double ld;
#define MOD (1000000000+7)
#define MOD1 (998244353)
#define PI 3.1415926535
#define pb push_back
#define setp() cout << setprecision(15)
#define all(x) x.begin(), x.end()
#define debug(x) cerr << #x << " is " << x << '\n';
const int N = 1e6+100, M = 1e5+10, F = 2147483646, K = 20;

int n, to[N];
string x, y;
map<string, int> s;
void solve(){
    cin >> n;
    int c = 1;
    for(int i = 0; i < n; ++i){
        cin >> x >> y;
        if(s[x] == 0) s[x] = c++;
        if(s[y] == 0) s[y] = c++;
        to[s[x] - 1] = s[y] - 1;
    }
    if(n&1){
        cout << -1;
        return;
    }
    int ans = n;
    for(int mask = 0; mask < (1<<n); ++mask){

        bool ok = 1;
        vector<int> v;

        for(int j = 0; j < n; ++j){
            if(!((1<<j)&mask)){
                v.pb(to[j]);
                if(to[j] == j) ok = 0;
                else if(!(to[to[j]] == j || ((1<<to[j])&mask))) ok = 0;
            }
        }
        sort(all(v));
        
        for(int j = 0; j < int(v.size()) - 1; ++j) if(v[j] == v[j + 1]) ok = 0;
        

        if(ok){
            if(ans > __builtin_popcount(mask)){
                ans = __builtin_popcount(mask);
            }
        }
    }
    cout << ans;
    
}





int main(){
    cin.tie(0); ios::sync_with_stdio(0);
    int T = 1, aa;
    // cin >> T;aa=T;
    while(T--){
        // cout << "Case #" << aa-T << ": ";
        solve();
        cout << '\n';
    }
    return 0;
 
}

Compilation message (stderr)

polygon.cpp: In function 'int main()':
polygon.cpp:65:16: warning: unused variable 'aa' [-Wunused-variable]
   65 |     int T = 1, aa;
      |                ^~

• Subtask 1: 21 / 21
• Subtask 2: 0 / 25
• Subtask 3: 0 / 29
• Subtask 4: 0 / 25