Submission #563348

#	Time	Username	Problem	Language	Result	Execution time	Memory
563348		tranxuanbach	Swap (BOI16_swap)	C++17	0 / 100	1 ms	340 KiB

swap

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

#define endl '\n'
#define fi first
#define se second
#define For(i, l, r) for (auto i = l; i < r; i++)
#define ForE(i, l, r) for (auto i = l; i <= r; i++)
#define FordE(i, l, r) for (auto i = l; i >= r; i--)
#define Fora(v, a) for (auto v: a)
#define bend(a) a.begin(), a.end()
#define isz(a) ((signed)a.size())

using ll = long long;
using ld = long double;
using pii = pair <int, int>;
using vi = vector <int>;
using vpii = vector <pair <int, int>>;
using vvi = vector <vector <int>>;

const int N = 2e5 + 5;

bool debug = 0;

int n;
int a[N];

int ans[N];

int willgoup[N];
int b[N]; // b[i] will go up and stay at i

int valdfs[N]; bool changedfs[N];

int dfs(int i){ // find the lowest index if start at i
    if (debug) cout << "dfs " << i << endl;
    if (!changedfs[i]){
        return valdfs[i];
    }
    if (b[i] == -1 or b[i] == 0){
        return (valdfs[i] = i);
    }
    if (willgoup[i * 2] == 1){
        return (valdfs[i] = dfs(i * 2));
    }
    if (willgoup[i * 2] == 0){
        return (valdfs[i] = dfs(i * 2 + 1));
    }
    return (valdfs[i] = min(dfs(i * 2), dfs(i * 2 + 1)));
}

void dfs_assign(int i, int j){
    if (debug) cout << "dfs_assign " << i << ' ' << j << endl;
    changedfs[i] = 1;
    if (i == j){
        if (i * 2 <= n){
            willgoup[i * 2] = 0;
        }
        if (i * 2 + 1 <= n){
            willgoup[i * 2 + 1] = 0;
        }
        b[i] = -1;
        return;
    }
    if (willgoup[i * 2] == 1){
        dfs_assign(i * 2, j);
        return;
    }
    if (willgoup[i * 2] == 0){
        dfs_assign(i * 2 + 1, j);
        return;
    }
    if (valdfs[i * 2] == j){
        willgoup[i * 2] = 1;
        dfs_assign(i * 2, j);
    }
    else{
        willgoup[i * 2] = 0;
        dfs_assign(i * 2 + 1, j);
    }
}

signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    // freopen("KEK.inp", "r", stdin);
    // freopen("KEK.out", "w", stdout);
    cin >> n;
    ForE(i, 1, n){
        cin >> a[i];
    }
    
    ForE(i, 1, n){
        willgoup[i] = -1;
        b[i] = -1;
        changedfs[i] = 1;
    }
    willgoup[1] = 0;
    
    vpii aa;
    ForE(i, 1, n){
        aa.emplace_back(a[i], i);
    }
    sort(bend(aa));
    
    Fora(elem, aa){
        int val, idx; tie(val, idx) = elem;
        if (debug) cout << "elem " << val << ' ' << idx << endl;
        if (willgoup[idx] != 0 and b[idx / 2] == -1){
            if (debug) cout << "fix up " << endl;
            willgoup[idx] = 1;
            if (idx % 2 == 0){
                willgoup[idx + 1] = 0;
            }
            b[idx / 2] = idx;
            ans[idx / 2] = val;
            continue;
        }
        int pos = n + 1, u = -1;
        if (willgoup[idx] != 1){
            int tpos = dfs(idx);
            if (debug) cout << "case 1 " << tpos << endl;
            if (pos > tpos){
                pos = tpos;
                u = idx;
            }
        }
        if (idx % 2 == 0 and willgoup[idx] != 0){
            int tpos = dfs(idx + 1);
            if (debug) cout << "case 2 " << tpos << endl;
            if (pos > tpos){
                pos = tpos;
                u = idx + 1;
            }
        }
        if (debug) cout << "ans " << pos << endl;
        ans[pos] = val;
        dfs_assign(u, pos);
    }
    ForE(i, 1, n){
        cout << ans[i] << ' ';
    } cout << endl;
}

/*
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INPUT:                                            |
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OUTPUT:                                           |
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*/

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