Submission #959474

#	Time	Username	Problem	Language	Result	Execution time	Memory
959474		Neco_arc	Ball Machine (BOI13_ballmachine)	C++17	100 / 100	166 ms	35592 KiB

ballmachine

#include <bits/stdc++.h>

#define ll long long
#define ull unsigned long long
#define all(x) x.begin(), x.end()
#define Neco "Ball Machine"
#define resp(x) sort(all(x)), x.resize(unique(all(x)) - x.begin())
#define getbit(x,i) ((x >> i)&1)
#define _left id * 2, l, mid
#define _right id * 2 + 1, mid + 1, r
#define cntbit(x) __builtin_popcountll(x)
#define fi(i, a, b) for(int i = a; i <= b; i++)
#define fid(i, a, b) for(int i = a; i >= b; i--)
#define maxn (int) 2e5 + 7

using namespace std;

const ll mod = 1e9 + 7; //972663749
const ll base = 911382323;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

ll GetRandom(ll l, ll r)
{
    return uniform_int_distribution<ll> (l, r)(rng);
}

int n, q, N, rt;
int cl[maxn], vt[maxn], cha[maxn][18];
int Min[maxn], h[maxn], a[maxn];
vector<int> edges[maxn];
set<int> S;

void pre_dfs(int u, int par) {
    for(int v : edges[u]) if(v != par) {
        pre_dfs(v, u);
        Min[u] = min(Min[u], Min[v]);
    }
}

int In[maxn], Out[maxn];
void dfs(int u, int par) {
    static int Time = 0;
    for(int v : edges[u]) if(v != par) {
        h[v] = h[u] + 1, cha[v][0] = u;
        fi(i, 1, 17) cha[v][i] = cha[cha[v][i - 1]][i - 1];
        dfs(v, u);
    }
    a[++N] = u, vt[u] = N;
}

int Add(int k, int ans = 0) {
    while(k--) {
        ans = a[*S.begin()];
        cl[a[*S.begin()]] = 1, S.erase(S.begin());
    }
    return ans;
}

int Del(int u, int ans = 0) {
    fid(i, 17, 0) if(cl[cha[u][i]]) u = cha[u][i], ans += (1 << i);
    S.insert(vt[u]), cl[u] = 0;
    return ans;
}

void solve()
{

    cin >> n >> q;

    int rt = 0;
    fi(i, 1, n) {
        Min[i] = i;
        int x; cin >> x;
        if(x == 0) rt = i;
        else edges[x].push_back(i);
    }

    pre_dfs(rt, 0);
    fi(i, 1, n) sort(all(edges[i]), [](int x, int y) { return Min[x] < Min[y]; } );
    dfs(rt, 0);

    fi(i, 1, n) S.insert(i);

    fi(i, 1, q) {
        int type, x;
        cin >> type >> x;
        if(type == 1) cout << Add(x) << '\n';
        else cout << Del(x) << '\n';
    }

}


int main()
{

    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

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


    int nTest = 1;
//    cin >> nTest;


    while(nTest--)
    {
        solve();
    }


    return 0;
}

Compilation message (stderr)

ballmachine.cpp: In function 'void dfs(int, int)':
ballmachine.cpp:43:16: warning: unused variable 'Time' [-Wunused-variable]
   43 |     static int Time = 0;
      |                ^~~~
ballmachine.cpp: In function 'int main()':
ballmachine.cpp:103:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  103 |         freopen(Neco".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
ballmachine.cpp:104:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  104 |         freopen(Neco".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
ballmachine.cpp: At global scope:
ballmachine.cpp:43:16: warning: 'Time' defined but not used [-Wunused-variable]
   43 |     static int Time = 0;
      |                ^~~~

• Subtask 1: 25 / 25
• Subtask 2: 30 / 30
• Subtask 3: 40 / 40
• Subtask 4: 5 / 5