제출 #172141

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
172141		emil_physmath	Longest beautiful sequence (IZhO17_subsequence)	C++17	0 / 100	110 ms	55180 KiB

subsequence

#include <algorithm>
#include <iostream>
#include <vector>
#include <set>
using namespace std;
typedef double ldouble;
typedef long long llong;
typedef unsigned int uint;
const int maxN = 100001;

vector<int> nei[400001];
int a[400001];
bool used[400001];

void DFS(int v, vector<int>& order)
{
    used[v] = true;
    for (int to: nei[v])
        if (!used[to])
            DFS(to, order);
    order.push_back(v);
}
bool Check(int n, int m, int len)
{
    if (len >= n)
    {
        llong sum = 0;
        for (int i = 1; i <= n; ++i)
            sum += a[i];
        if (sum >= 0) return false;
        for (int i = 2; i + n - 1 <= len; ++i)
        {
            sum -= a[i - 1];
            sum += a[i + n - 1];
            if (sum >= 0) return false;
        }
    }
    if (len >= m)
    {
        llong sum = 0;
        for (int i = 1; i <= m; ++i)
            sum += a[i];
        if (sum <= 0) return false;
        for (int i = 2; i + m - 1 <= len; ++i)
        {
            sum -= a[i - 1];
            sum += a[i + m - 1];
            if (sum <= 0) return false;
        }
    }
    return true;
}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

    int t;
    cin >> t;
    while (t--)
    {
        int n, m;
        cin >> n >> m;
        int ans = 0;
        int l = 1/*max(n, m) - 1*/, r = 400000/*max(n, m) + max(n, m) % min(n, m)*/;
        while (l <= r)
        {
            int len = (l + r) / 2;
            for (int i = 0; i <= len; ++i)
            {
                used[i] = false;
                vector<int>().swap(nei[i]);
            }
            for (int i = 1; i <= len; ++i)
            {
                if (i - n >= 0)
                    nei[i].push_back(i - n);
                if (i - m >= 0)
                    nei[i - m].push_back(i);
            }
            vector<int> order;
            for (int i = 0; i <= len; ++i)
                if (!used[i])
                    DFS(i, order);
            reverse(order.begin(), order.end());
            vector<int> pref(len);
            for (int i = 0; i < order.size(); ++i)
                pref[order[i]] = i;
            for (int i = 1; i < pref.size(); ++i)
                pref[i] -= pref[0];
            pref[0] = 0;
            for (int i = 1; i <= len; ++i)
                a[i] = pref[i] - pref[i - 1];
            if (Check(n, m, len))
            {
                ans = len;
                l = len + 1;
            }
            else
                r = len - 1;
        }
        cout << ans << endl;
    }
}

컴파일 시 표준 에러 (stderr) 메시지

subsequence.cpp: In function 'int main()':
subsequence.cpp:88:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int i = 0; i < order.size(); ++i)
                             ~~^~~~~~~~~~~~~~
subsequence.cpp:90:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int i = 1; i < pref.size(); ++i)
                             ~~^~~~~~~~~~~~~

• Subtask 1: 0 / 7
• Subtask 2: 0 / 16
• Subtask 3: 0 / 17
• Subtask 4: 0 / 60