Submission #1098264

#	Time	Username	Problem	Language	Result	Execution time	Memory
1098264		Zero_OP	Spring cleaning (CEOI20_cleaning)	C++14	9 / 100	25 ms	7516 KiB

cleaning

#include<bits/stdc++.h>

using namespace std;

#define sz(v) (int)v.size()
#define all(v) begin(v), end(v)
#define compact(v) v.erase(unique(all(v)), end(v))
#define dbg(v) "[" #v " = " << (v) << "]"
#define file(name) if(fopen(name".inp", "r")) {freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
#define rep(i, l, r) for(int i = (l); i < (r); ++i)

using ll = long long;
using vi = vector<int>;
using vl = vector<long long>;
using ld = long double;

template<typename T>
    bool minimize(T& a, const T& b){
        if(a > b){
            return a = b, true;
        }  return false;
    }

template<typename T>
    bool maximize(T& a, const T& b){
        if(a < b){
            return a = b, true;
        } return false;
    }

template<int dimension, typename T>
struct tensor : public vector<tensor<dimension - 1, T>> {
    static_assert(dimension > 0, "Dimension must be positive !\n");
    template<typename... Args>
    tensor(int n = 0, Args... args) : vector<tensor<dimension - 1, T>> (n, tensor<dimension - 1, T>(args...)) {}
};

template<typename T>
struct tensor<1, T> : public vector<T> {
    tensor(int n = 0, T val = T()) : vector<T>(n, val) {}
};

const int MAX = 1e5 + 5;

int n, q;
vector<int> adj[MAX];

namespace subtask1{
    bool check(){
        return sz(adj[1]) == n - 1 && q == 1;
    }

    int cnt[MAX];

    void solve(){
        int D;
        cin >> D;

        for(int i = 1; i <= D; ++i){
            int u;
            cin >> u;
            ++cnt[u];
        }

        int cost = 0;
        int leaves = 0;
        for(int i = 2; i <= n; ++i){
            if(cnt[i] > 0){
                leaves += cnt[i];
                cost += 2 * (cnt[i] / 2);
                cnt[i] &= 1;
                if(cnt[i] > 0) cost += 2;
            } else{
                cost += 1;
                leaves += 1;
            }
        }

        if(leaves & 1) cout << -1 << '\n';
        else cout << cost << '\n';
    }
}

namespace subtask2{
    bool check(){
        if(q != 1) return false;
        for(int i = 1; i <= n; ++i){
            for(auto j : adj[i]){
                if(abs(i - j) > 1){
                    return false;
                }
            }
        }
        return true;
    }

    int cnt[MAX];

    void solve(){
        int D;
        cin >> D;
        for(int i = 0; i < D; ++i){
            int u;
            cin >> u;
            ++cnt[u];
        }

        //greedy

        if(D & 1){
            cout << -1 << '\n';
            return;
        }

        int cost = n - 1; //(1, n)
        int last = -1;
        for(int i = 2; i < n; ++i){
            cost += 2 * (cnt[i] / 2);
            cnt[i] &= 1;

            if(cnt[i] == 1){
                if(last != -1) cost += abs(last - i) + 2, last = -1;
                else last = i;
            }
        }

        assert(last == -1);

        cout << cost << '\n';
    }
}

namespace subtask3{

}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    if(fopen("task.inp", "r")){
        freopen("task.inp", "r", stdin);
        freopen("task.out", "w", stdout);
    }

    cin >> n >> q;
    for(int i = 1; i < n; ++i){
        int u, v;
        cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }

    if(subtask1::check()){
        return subtask1::solve(), 0;
    }

    if(subtask2::check()){
        return subtask2::solve(), 0;
    }

    return 0;
}

Compilation message (stderr)

cleaning.cpp: In function 'int main()':
cleaning.cpp:142:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  142 |         freopen("task.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
cleaning.cpp:143:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  143 |         freopen("task.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 0
• Subtask 2: 0 / 9
• Subtask 3: 9 / 9
• Subtask 4: 0 / 16
• Subtask 5: 0 / 19
• Subtask 6: 0 / 17
• Subtask 7: 0 / 30