Submission #1090547

#	Time	Username	Problem	Language	Result	Execution time	Memory
1090547		BigBadBully	Fire (BOI24_fire)	C++17	13 / 100	57 ms	14720 KiB

Main

#include <bits/stdc++.h>
#define ff first
#define ss second
#define int long long
#define pii pair<int, int>
#define ff first
#define ss second
using namespace std;
const int inf = 1e17;
const int mod = 998244353;


void solve()
{
    int n,m;
    cin >> n >> m;
    vector<pii> v(n);
    for (int i = 0; i< n; i++)
    {
        cin >> v[i].ff >> v[i].ss;
        while(v[i].ff>v[i].ss)
            v[i].ss+=m;
    }
    sort(v.begin(),v.end());
    {
    vector<bool> del(n);
    int maxi = 0;
    for (int i = 0; i < n;i ++)
    {
        if (v[i].ss <= maxi)
            del[i] = 1;
        maxi = max(maxi,v[i].ss);
    }
    vector<pii> neu;
    for (int i = 0; i < n; i++)
        if (!del[i])
            neu.push_back(v[i]);
    n = neu.size();
    v = neu;
    }
    {
    vector<bool> del(n);
    int mini = v[n-1].ss;
    for (int i = n-1; i >= 0;i--)
    {
        if (v[i].ff >= mini)
            del[i] = 1;
        mini = min(mini,v[i].ff);
    }
    vector<pii> neu;
    for (int i = 0; i < n; i++)
        if (!del[i])
            neu.push_back(v[i]);
    n = neu.size();
    v = neu;
    }
    for (int i = 0; i< n;i++)
        v[i].ss%=m;
    /*for (int i = 0; i < n; i++)
        cout << v[i].ff << ' ' << v[i].ss << '\n';*/
    int prev = v[0].ss;
    int used = 1;
    if (v[0].ff != 0)
    {
        cout << -1 << '\n';
        return;
    }
    for (int i = 1; i < n; i++)
    {
        if (v[i].ff > prev)
        {
            used++;
            prev = v[i-1].ss;
            if (v[i].ff > prev)
            {
                cout << -1 << '\n';
                return;
            }
        }
        if (prev != 0 && v[i].ss == 0)
        {
            used++;
            break;
        }
    }
    cout << used << '\n';
}


signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    
    solve();
}

• Subtask 1: 0 / 14
• Subtask 2: 0 / 17
• Subtask 3: 0 / 9
• Subtask 4: 13 / 13
• Subtask 5: 0 / 21
• Subtask 6: 0 / 26