Submission #245621

#	Time	Username	Problem	Language	Result	Execution time	Memory
245621		thecodingwizard	Swap (BOI16_swap)	C++11	68 / 100	345 ms	262144 KiB

swap

#include <bits/stdc++.h>

using namespace std;

const int maxn = 200000;

int n, A[maxn+10];
vector<int> dp[maxn+10][36], tmp1, tmp2;
bool v[maxn+10][36];

void merge(vector<int> &res, int root, vector<int> &L, vector<int> &R) {
    res.push_back(root);
    for (int len = 1, i = 0, j = 0; i < L.size() || j < R.size(); i += len, j += len, len *= 2) {
        for (int k = 0; k < len && i+k<L.size(); k++) res.push_back(L[i+k]);
        for (int k = 0; k < len && i+k<R.size(); k++) res.push_back(R[i+k]);
    }
}

int main() {
    cin.tie(0); ios_base::sync_with_stdio(0);
    cin >> n; for (int i = 1; i <= n; i++) cin >> A[i];
    for (int i = 1; i <= n; i++) for (int j = 0; j < 36; j++) v[i][j] = false;
    v[1][0] = 1;
    for (int i = 1; 2*i+1 <= n; i++) {
        for (int j = 0; j < 36; j++) {
            if (!v[i][j]) continue;
            int idx = (i>>(j/2))<<(j&1);
            int cur = A[idx];
            int l = i*2, r = i*2+1;
            int L = A[l], R = A[r];

            v[2*i][0] = v[2*i+1][0] = true;

            if (L<cur&&L<R) {
                v[2*i][j+2] = true;
            }
            if (R<cur&&R<L) {
                v[2*i+1][3] = true;
                v[2*i][j+2] = true;
                v[2*i+1][j+2] = true;
            }
        }
    }
    for (int i = n; i; i--) {
        int l = i*2, r = i*2+1;
        int L = A[l], R = A[r];
        for (int j = 0; j < 36; j++) {
            if (!v[i][j]) continue;
            int idx = (i>>(j/2))<<(j&1);
            int cur = A[idx];

            if (l > n && r > n) {
                dp[i][j] = {cur};
                continue;
            } else if (r > n) {
                dp[i][j] = {min(A[l],cur),max(A[l],cur)};
                continue;
            }

            // no swap
            if (cur < L && cur < R) {
                merge(dp[i][j], cur, dp[l][0], dp[r][0]);
                continue;
            }

            // swap left
            if (cur > L && L < R) {
                merge(dp[i][j], L, dp[l][j+2], dp[r][0]);
                continue;
            }

            if (R < cur && R < L) {
                tmp1 = {}, tmp2 = {};
                // swap right
                merge(tmp1, R, dp[l][0], dp[r][j+2]);
                // swap both
                merge(tmp2, R, dp[l][j+2], dp[r][3]);
                dp[i][j] = min(tmp1, tmp2);
            }
        }

        if (l <= n) {
            for (int j = 0; j < 36; j++) if (v[l][j]) vector<int>().swap(dp[l][j]);
        }
        if (r <= n) {
            for (int j = 0; j < 36; j++) if (v[r][j]) vector<int>().swap(dp[r][j]);
        }
    }
    for (int v : dp[1][0]) cout << v << " ";
    cout << "\n";
    return 0;
}

Compilation message (stderr)

swap.cpp: In function 'void merge(std::vector<int>&, int, std::vector<int>&, std::vector<int>&)':
swap.cpp:13:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int len = 1, i = 0, j = 0; i < L.size() || j < R.size(); i += len, j += len, len *= 2) {
                                     ~~^~~~~~~~~~
swap.cpp:13:55: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int len = 1, i = 0, j = 0; i < L.size() || j < R.size(); i += len, j += len, len *= 2) {
                                                     ~~^~~~~~~~~~
swap.cpp:14:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int k = 0; k < len && i+k<L.size(); k++) res.push_back(L[i+k]);
                                    ~~~^~~~~~~~~
swap.cpp:15:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int k = 0; k < len && i+k<R.size(); k++) res.push_back(R[i+k]);
                                    ~~~^~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 11 / 11
• Subtask 3: 27 / 27
• Subtask 4: 20 / 20
• Subtask 5: 0 / 32