oj.uz

답안 #366882

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
366882 2021-02-15T15:55:11 Z ACmachine Love Polygon (BOI18_polygon) C++17
46 / 100
 1167 ms 14496 KB 
#include <bits/stdc++.h>
using namespace std;

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename T, typename U> using ordered_map = tree<T, U, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

typedef long long ll;
typedef long double ld;
typedef double db;
typedef string str;

typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
typedef vector<str> vstr;

#define FOR(i,j,k,in) for(int i=(j); i < (k);i+=in)
#define FORD(i,j,k,in) for(int i=(j); i >=(k);i-=in)
#define REP(i,b) FOR(i,0,b,1)
#define REPD(i,b) FORD(i,b,0,1)
#define pb push_back 
#define mp make_pair
#define ff first
#define ss second
#define all(x) begin(x), end(x)
#define rsz resize 
#define MANY_TESTS int tcase; cin >> tcase; while(tcase--)
	
const double EPS = 1e-9;
const int MOD = 1e9+7; // 998244353;
const ll INFF = 1e18;
const int INF = 1e9;
const ld PI = acos((ld)-1);
const vi dy = {1, 0, -1, 0, -1, 1, 1, -1};
const vi dx = {0, 1, 0, -1, -1, 1, -1, 1};

#ifdef DEBUG
#define DBG if(1)
#else
#define DBG if(0)
#endif

#define dbg(x) cout << "(" << #x << " : " << x << ")" << endl;
// ostreams
template <class T, class U>
ostream& operator<<(ostream& out, const pair<T, U> &par) {out << "[" << par.first << ";" << par.second << "]"; return out;}
template <class T>
ostream& operator<<(ostream& out, const set<T> &cont) { out << "{"; for( const auto &x:cont) out << x << ", "; out << "}"; return out; }
template <class T, class U>
ostream& operator<<(ostream& out, const map<T, U> &cont) {out << "{"; for( const auto &x:cont) out << x << ", "; out << "}"; return out; }
template<class T>
ostream& operator<<(ostream& out, const vector<T> &v){ out << "[";  REP(i, v.size()) out << v[i] << ", ";  out << "]"; return out;}
// istreams
template<class T>
istream& operator>>(istream& in, vector<T> &v){ for(auto &x : v) in >> x; return in; }
template<class T, class U>
istream& operator>>(istream& in, pair<T, U> &p){ in >> p.ff >> p.ss; return in; }
//searches
template<typename T, typename U>
T bsl(T lo, T hi, U f){ hi++; T mid; while(lo < hi){ mid = (lo + hi)/2; f(mid) ? hi = mid : lo = mid+1; } return lo; }
template<typename U>
double bsld(double lo, double hi, U f, double p = 1e-9){ int r = 3 + (int)log2((hi - lo)/p); double mid; while(r--){ mid = (lo + hi)/2; f(mid) ? hi = mid : lo = mid; } return (lo + hi)/2; }
template<typename T, typename U>
T bsh(T lo, T hi, U f){ lo--; T mid; while(lo < hi){ mid = (lo + hi + 1)/2; f(mid) ? lo = mid : hi = mid-1; } return lo; }
template<typename U>
double bshd(double lo, double hi, U f, double p = 1e-9){ int r = 3+(int)log2((hi - lo)/p); double mid; while(r--){ mid = (lo + hi)/2; f(mid) ? lo = mid : hi = mid; } return (lo + hi)/2; }
// some more utility functions
template<typename T>
pair<T, int> get_min(vector<T> &v){ typename vector<T> :: iterator it = min_element(v.begin(), v.end()); return mp(*it, it - v.begin());}
template<typename T>
pair<T, int> get_max(vector<T> &v){ typename vector<T> :: iterator it = max_element(v.begin(), v.end()); return mp(*it, it - v.begin());}        
template<typename T> bool ckmin(T& a, const T& b){return b < a ? a = b , true : false;}
template<typename T> bool ckmax(T& a, const T& b){return b > a ? a = b, true : false;}

   
struct dsu{
    vector<int> e;
    dsu(){};
    dsu(int n){
        e.resize(n, -1);
    }
    int find(int x){ return (e[x] < 0 ? x : e[x] = find(e[x])); }
    int size(int x){ return -e[find(x)]; }
    int sameSet(int a, int b){ return find(a) == find(b); }
    bool join(int a, int b){
        a = find(a); b = find(b);
        if(a == b) return false;
        if(e[a] > e[b]) swap(a, b);
        e[a] += e[b]; e[b] = a;
        return true;
    }
};
int solve_dp(vector<int> &g, int n){
    vector<vi> mat(n, vi(n));
    REP(i, n) mat[i][g[i]] = 1;
    vi dp((1 << n), INF);
    dp[0] = 0; 
    REP(mask, (1 << n)){
        REP(i, n){
            REP(j, n){
                if(i == j) continue;
                if(!(mask & (1 << i)) && !(mask &(1 << j))){
                    dp[mask|(1 << i)|(1 << j)] = min(dp[mask|(1 << i)|(1 << j)], dp[mask] + (2 - mat[i][j] - mat[j][i]));
                }
            }
        }
    }
    return dp[(1 << n) - 1];
}
int main(){
 	ios_base::sync_with_stdio(false);
 	cin.tie(NULL); cout.tie(NULL);
	int n; cin >> n;
    if(n % 2 == 1){
        cout << -1 << "\n";
        return 0;
    }
    vector<int> g(n);
    int curr_id = 0;
    map<string, int> name_to_id;
    REP(i, n){
        string s, t;
        cin >> s >> t;
        int u, v;
        if(name_to_id.find(s) == name_to_id.end())
            name_to_id[s] = curr_id++;
        if(name_to_id.find(t) == name_to_id.end())
            name_to_id[t] = curr_id++;
        u = name_to_id[s];
        v = name_to_id[t];
        g[u] = v;
    }
    if(n <= 20){
        cout << solve_dp(g, n) << "\n";
        return 0;
    }
    vector<int> cycle_begins;
    vector<int> visited(n, -1);
    function<void(int, int, bool)> dfs = [&](int v, int id, bool cycle_finding){
        visited[v] = id;
        if(visited[g[v]] == -1) 
            dfs(g[v], id, cycle_finding);
        else{
            if(visited[g[v]] == visited[v] && cycle_finding)
                cycle_begins.pb(v);
        }
    };
    int cid = 0;
    REP(i, n){
        if(visited[i] == -1){
            dfs(i, cid, true);
            cid++;
        }
    }
    fill(all(visited), -1);
    cid = 0;
    REP(i, cycle_begins.size()){
        if(visited[cycle_begins[i]] == -1){
            dfs(cycle_begins[i], cid, false); 
            cid++;
        }
    }
    int cycle_ids = cid;
    vector<int> chain_begins;
    vector<int> indeg(n, 0);
    REP(i, n){
        indeg[g[i]]++; 
    }
    REP(i, n){
        if(indeg[i] == 0) chain_begins.pb(i);
    }
    int res = 0; // sekame chainy
    vector<bool> used(n, false);
    function<void(int)> dfs2 = [&](int v){
        if(!used[v] && !used[g[v]] && v != g[v]){
            res++;
            used[v] = used[g[v]] = true;
        }
        if(visited[g[v]] == -1){
            dfs2(g[v]);
        }
    };
    for(int st : chain_begins){
        dfs2(st);
    }
    dsu d(n); 
    REP(i, n){
        if(!used[i]){
            if(!used[g[i]]){
                if(g[g[i]] == i && i != g[i]){
                    used[i] = used[g[i]] = true;
                    continue;
                }
                d.join(i, g[i]);
            }
        }
    }
    REP(i, n){
        if(!used[i]){
            if(d.find(i) == i){
                int sz = d.size(i);
                if(sz % 2 == 1) res += sz / 2 + 1;
                else res += sz / 2;
            }
        }
    }
    cout << res << "\n";
    return 0;
}

Compilation message

polygon.cpp: In function 'int main()':
polygon.cpp:26:40: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 | #define FOR(i,j,k,in) for(int i=(j); i < (k);i+=in)
      |                                        ^
polygon.cpp:28:18: note: in expansion of macro 'FOR'
   28 | #define REP(i,b) FOR(i,0,b,1)
      |                  ^~~
polygon.cpp:166:5: note: in expansion of macro 'REP'
  166 |     REP(i, cycle_begins.size()){
      |     ^~~
polygon.cpp:172:9: warning: unused variable 'cycle_ids' [-Wunused-variable]
  172 |     int cycle_ids = cid;
      |         ^~~~~~~~~

Subtask #1
21.0 / 21.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1144 ms 4460 KB Output is correct
2 Correct 1156 ms 4460 KB Output is correct
3 Correct 1154 ms 4460 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 0 ms 364 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 1153 ms 4460 KB Output is correct
8 Correct 1155 ms 4460 KB Output is correct
9 Correct 1167 ms 4460 KB Output is correct
10 Correct 1154 ms 4460 KB Output is correct
11 Correct 1141 ms 4460 KB Output is correct
12 Correct 1 ms 364 KB Output is correct
13 Correct 0 ms 364 KB Output is correct
14 Correct 1 ms 364 KB Output is correct
15 Correct 1 ms 364 KB Output is correct

Subtask #2
25.0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 0 ms 364 KB Output is correct
3 Correct 1 ms 364 KB Output is correct
4 Correct 254 ms 13820 KB Output is correct
5 Correct 278 ms 9964 KB Output is correct
6 Correct 262 ms 14496 KB Output is correct
7 Correct 1 ms 364 KB Output is correct

Subtask #3
0 / 29.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 242 ms 9964 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1144 ms 4460 KB Output is correct
2 Correct 1156 ms 4460 KB Output is correct
3 Correct 1154 ms 4460 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 0 ms 364 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 1153 ms 4460 KB Output is correct
8 Correct 1155 ms 4460 KB Output is correct
9 Correct 1167 ms 4460 KB Output is correct
10 Correct 1154 ms 4460 KB Output is correct
11 Correct 1141 ms 4460 KB Output is correct
12 Correct 1 ms 364 KB Output is correct
13 Correct 0 ms 364 KB Output is correct
14 Correct 1 ms 364 KB Output is correct
15 Correct 1 ms 364 KB Output is correct
16 Correct 1 ms 364 KB Output is correct
17 Correct 0 ms 364 KB Output is correct
18 Correct 1 ms 364 KB Output is correct
19 Correct 254 ms 13820 KB Output is correct
20 Correct 278 ms 9964 KB Output is correct
21 Correct 262 ms 14496 KB Output is correct
22 Correct 1 ms 364 KB Output is correct
23 Incorrect 242 ms 9964 KB Output isn't correct
24 Halted 0 ms 0 KB -