Submission #1172708

#	Time	Username	Problem	Language	Result	Execution time	Memory
1172708		anmattroi	Mechanical Doll (IOI18_doll)	C++17	100 / 100	72 ms	11164 KiB

doll

#include "doll.h"
#include <bits/stdc++.h>
#define maxn 400005
#define fi first
#define se second
using namespace std;
using ii = pair<int, int>;

int N, nho, nt, cnt;
vector<int> a, X, Y;
int parity[maxn];

int build(int lo, int hi) {
    if (nho >= hi-lo+1) {
        nho -= hi-lo+1;
        return 1;
    }
    if (lo == hi)
        return INT_MAX/2;

    int mid = (lo + hi) >> 1, cur = ++nt;
    X[cur-1] = -build(lo, mid);
    Y[cur-1] = -build(mid+1, hi);
    return cur;
}

void dfs(int u, int lo, int hi) {
    if (lo == hi) {
        X[u-1] = a[cnt]; ++cnt;
        return;
    }
    int next_destination = (parity[u] ? -Y[u-1] : -X[u-1]);
    parity[u] ^= 1;
    if (next_destination == 1) return;
    int mid = (lo + hi) >> 1;
    if (next_destination == -X[u-1]) {
        if (lo == mid) {
            X[u-1] = a[cnt]; ++cnt;
            return;
        }
        dfs(next_destination, lo, mid);
    }
    else {
        if (mid+1 == hi) {
            Y[u-1] = a[cnt]; ++cnt;
            return;
        }
        dfs(next_destination, mid+1, hi);
    }
}


void create_circuit(int M, vector<int> A) {
    N = A.size();
    a = A; nt = cnt = 0;
    if (N == 1) {
        vector<int> C(M+1, 0);
        C[0] = A[0];
        C[A[0]] = 0;
        answer(C, {}, {});
        return;
    }
    int k = __lg(N) + 1;
    nho = (1<<k)-N-1;

    vector<int> C(M+1, -1);
    ++nt;
    X.assign(N + __lg(N+1) + 100, -1);
    Y.assign(N + __lg(N+1) + 100, -1);

    X[0] = -build(0, (1<<k)/2-1);
    Y[0] = -build((1<<k)/2, (1<<k)-1);
    a.emplace_back(0);
    X.resize(nt);
    Y.resize(nt);

    for (int i = 1; i <= nt; i++) parity[i] = 0;
    for (int i = 0; i < (1<<k); i++) dfs(1, 0, (1<<k)-1);
    answer(C, X, Y);
}
/*
4 4
1 2 1 3
*/

• Subtask 1: 2 / 2
• Subtask 2: 4 / 4
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 18 / 18
• Subtask 6: 56 / 56