oj.uz

Submission #467833

# Submission time Handle Problem Language Result Execution time Memory
467833 2021-08-24T21:58:38 Z Ozy Love Polygon (BOI18_polygon) C++17
25 / 100
 292 ms 28168 KB 
#include <iostream>
#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i = (a); i <= (b); i++)
#define repa(i,a,b) for(int i = (a); i >= (b); i--)
#define lli long long int
#define debug(a) cout << #a << " = " << a << endl
#define debugsl(a) cout << #a << " = " << a << ", "

#define MAX 100000

pair<lli,lli> ult;
lli n,a,b,cont,res,cant;
lli dp[2][MAX+2],dir[MAX+2],visitados[MAX+2];
string A,B;
map<string, lli> mapa;
vector<lli> hijos[MAX+2];

void dfs(lli pos, lli marca) {

    cant++;
    visitados[pos] = marca;
    dp[0][pos] = 0;
    dp[1][pos] = 0;

    lli MIN = INT_MAX;
    lli sum = 0;
    lli x;

    bool tengoH = false;
    for(auto h : hijos[pos]) {
        if (visitados[h] == marca) continue;

        tengoH = true;
        dfs(h,marca);

        sum += dp[1][h];
        x = dp[0][h] - dp[1][h];
        if (x < MIN) MIN = x;
    }

    if (!tengoH) {
        dp[0][pos] = 0;
        dp[1][pos] = 1;
        return;
    }

    dp[0][pos] = sum;

    sum += MIN;
    dp[1][pos] = sum + 1;

}

pair<lli,lli> busca(lli pos) {
    while (visitados[pos] == 0) {
        visitados[pos] = 1;
        if (visitados[dir[pos]] == 1) return {pos,dir[pos]};
        pos = dir[pos];
    }
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    cin >> n;

    cont = 1;

    rep(i,1,n) {
        cin >> A >> B;

        if (mapa.find(A) == mapa.end()) mapa[A] = cont++;
        if (mapa.find(B) == mapa.end()) mapa[B] = cont++;
        a = mapa[A];
        b = mapa[B];

        dir[a] = b;

        hijos[b].push_back(a);
        hijos[a].push_back(b);
    }
    if (n&1) {
        cout << "-1";
        return 0;
    }

    res = 0;
    rep(i,1,n) if (visitados[i] == 0){

        ult = busca(i);

        cant = 0;
        dfs(ult.first, 2);
        a = dp[1][ult.first];
        if (cant == 2) continue;

        if (ult.second != ult.first) {
            dfs(ult.second, 3);
            a = min(a, dp[1][ult.second]);
        }

        res += a;
    }

    cout << res;
}

Compilation message

polygon.cpp: In function 'std::pair<long long int, long long int> busca(long long int)':
polygon.cpp:61:1: warning: control reaches end of non-void function [-Wreturn-type]
   61 | }
      | ^

Subtask #1
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2636 KB Output is correct
2 Correct 2 ms 2636 KB Output is correct
3 Correct 2 ms 2636 KB Output is correct
4 Correct 2 ms 2672 KB Output is correct
5 Correct 2 ms 2636 KB Output is correct
6 Correct 2 ms 2672 KB Output is correct
7 Correct 2 ms 2636 KB Output is correct
8 Incorrect 2 ms 2676 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2636 KB Output is correct
2 Correct 2 ms 2636 KB Output is correct
3 Correct 2 ms 2668 KB Output is correct
4 Correct 292 ms 27260 KB Output is correct
5 Correct 260 ms 18780 KB Output is correct
6 Correct 292 ms 28168 KB Output is correct
7 Correct 287 ms 16456 KB Output is correct

Subtask #3
0 / 29.0

# Verdict Execution time Memory Grader output
1 Incorrect 275 ms 19284 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2636 KB Output is correct
2 Correct 2 ms 2636 KB Output is correct
3 Correct 2 ms 2636 KB Output is correct
4 Correct 2 ms 2672 KB Output is correct
5 Correct 2 ms 2636 KB Output is correct
6 Correct 2 ms 2672 KB Output is correct
7 Correct 2 ms 2636 KB Output is correct
8 Incorrect 2 ms 2676 KB Output isn't correct
9 Halted 0 ms 0 KB -