Submission #195590

#	Time	Username	Problem	Language	Result	Execution time	Memory
195590		karma	Ball Machine (BOI13_ballmachine)	C++14	20.95 / 100	927 ms	21944 KiB

ballmachine

#include <bits/stdc++.h>
#define pb          emplace_back
#define ll          long long
#define fi          first
#define se          second
#define mp          make_pair
//#define int         int64_t

using namespace std;

const int N = (int)1e5 + 2;
const int logN = 20;

int p[N][logN + 1], del[N], d[N], deg[N];
int root, n, q, x, k, low, high, mid;
vector<int> a[N];
set<int> leaf;

void DFS(int u) {
    deg[u] = a[u].size();
    for(int i = 1; i <= logN; ++i) p[u][i] = p[p[u][i - 1]][i - 1];
    if(!deg[u]) leaf.insert(u);
    for(int v: a[u]) d[v] = d[u] + 1, DFS(v);
}

int Node(int x, int step) {
    for(int i = logN; i >= 0; --i)
        if(step >= (1 << i)) x = p[x][i], step -= (1 << i);
    return x;
}

int32_t main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    #define Task        "test"
    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) {
        cin >> p[i][0]; a[p[i][0]].pb(i);
        if(!p[i][0]) root = i;
    }
    DFS(root);
    while(q --) {
        cin >> x >> k;
        if(x == 1) {
            while(k --) {
                x = *leaf.begin(); leaf.erase(x);
                if(--deg[p[x][0]] == 0) leaf.insert(p[x][0]);
                del[x] = 1;
            }
            cout << x << '\n';
        } else {
            low = 0, high = d[k];
            while(low <= high) {
                mid = (low + high) >> 1;
                if(del[Node(k, mid)]) low = mid + 1;
                else high = mid - 1;
            }
            x = Node(k, high), del[x] = 0, leaf.insert(x);
            if(++deg[p[x][0]] == 1) leaf.erase(p[x][0]);
            cout << d[k] - d[x] << '\n';
        }
    }
}

Compilation message (stderr)

ballmachine.cpp: In function 'int32_t main()':
ballmachine.cpp:37:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
         freopen(Task".inp", "r", stdin);
         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
ballmachine.cpp:38:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
         freopen(Task".out", "w", stdout);
         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 25
• Subtask 2: 10.714285714285714 / 30
• Subtask 3: 8.571428571428571 / 40
• Subtask 4: 1.6666666666666667 / 5