Submission #490769

#	Time	Username	Problem	Language	Result	Execution time	Memory
490769		Rainbowbunny	Swap (BOI16_swap)	C++17	100 / 100	48 ms	5956 KiB

swap

#include <bits/stdc++.h>
using namespace std;

const int MAXN = 4e5 + 5;
const int INF = 1e9;

int n;
int A[MAXN], state[MAXN];

int Findup(int id)
{
    int ans = INF;
    while(id > 0)
    {
        // cout << id << "o" << endl;
        // cout << A[id] << endl;
        if(state[id] != 1)
        {
            ans = min(ans, A[id]);
        }
        if(state[id] == 0)
        {
            return ans;
        }
        if(id & 1)
        {
            if(state[id - 1] == 1)
            {
                return min(ans, A[id - 1]);
            }
            if(state[id - 1] == -1)
            {
                ans = min(ans, A[id - 1]);
            }
        }
        id >>= 1;
    }
}

void Move(int id, int val)
{
    while(id)
    {
        // cout << id << "H" << endl;
        if(A[id] == val)
        {
            state[id] = 0;
            return;
        }
        if(id & 1)
        {
            if(A[id - 1] == val)
            {
                state[id - 1] = 1;
                state[id] = 1;
                break;
            }
            else
            {
                state[id - 1] = 0; 
            }
        }
        state[id] = 1;
        id >>= 1;
    }
}

int main()
{
    // freopen("Input.txt", "r", stdin);
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin >> n;
    for(int i = 1; i <= n; i++)
    {
        cin >> A[i];
    }
    for(int i = n + 1; i <= 2 * n + 1; i++)
    {
        A[i] = INF;
    }
    for(int i = 1; i <= 2 * n; i++)
    {
        state[i] = -1;
    }
    state[1] = 0;
    for(int i = 1; i <= n; i++)
    {
        int v = Findup(i);
        int tmp = min({v, A[2 * i], A[2 * i + 1]});
        if(tmp == v)
        {
            Move(i, v);
            state[2 * i] = 0;
            state[2 * i + 1] = 0;
        }
        else if(tmp == A[2 * i])
        {
            state[2 * i] = 1;
            state[2 * i + 1] = 0;
        }
        else if(tmp == A[2 * i + 1])
        {
            state[2 * i + 1] = 1;
        }
        // for(int j = 2; j <= n; j++)
        // {
        //     cout << state[j] << ' ';
        // }
        // cout << '\n';
        cout << tmp << ' ';
    } 
    cout << '\n';
}

Compilation message (stderr)

swap.cpp: In function 'int Findup(int)':
swap.cpp:38:1: warning: control reaches end of non-void function [-Wreturn-type]
   38 | }
      | ^

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