Submission #1090697

#	Time	Username	Problem	Language	Result	Execution time	Memory
1090697		BigBadBully	Fire (BOI24_fire)	C++17	35 / 100	75 ms	46004 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;
 
 
int solve(int n,int m,vector<pii> v)
{
    for (int i = 0;i  < n; i++)
        if (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;
   
    {
        int bigie = 0;
        for (int i = 0; i < n; i++)
            if (v[i].ff > v[i].ss)
                bigie = max(bigie,v[i].ss);
        vector<bool> del(n);
        for (int i = 0; i < n; i++)
            if (v[i].ff < v[i].ss && v[i].ss < bigie)
                del[i] = 1;
        vector<pii> neu;
        for (int i = 0; i < n; i++)
            if (!del[i])
                neu.push_back(v[i]);
        n = neu.size();
        v = neu;        
    }
    int oldn = n;
    vector<pii> normalni;

    for (int i = 0; i < n; i++)
        if (v[i].ff < v[i].ss)
            normalni.push_back(v[i]);
    n = normalni.size();
    if (!n)
    {
        return -1;
    }
    vector<int> nxt(n);
    
    for (int i = 0; i < n-1; i++)
    {
        int l = i;
        int r = n;
        while (r-l>1)
        {
            int mid = l+r>>1;
            if (normalni[mid].ff > normalni[i].ss)
                r = mid;
            else
                l = mid;
        }
        if (l == i)
        {
           
            return -1;
        }
        nxt[i] = l;

    }
    
    nxt[n-1] = -1;
    vector<vector<int>> lifts(20,vector<int>(n));
    lifts[0] = nxt;
    for (int j = 1; j < 20; j++)
        for (int i = 0; i < n; i++)
        {
            if (lifts[j-1][i] == -1)
                lifts[j][i] = -1;
            else
                lifts[j][i] = lifts[j-1][lifts[j-1][i]];
        }
    n = oldn;
    int normala = normalni.size();
    int mini= inf;
    for (int fix = 0; fix < n; fix++)
    {
        int f = v[fix].ff, s = v[fix].ss;
        int beg;
        if (v[fix].ff > v[fix].ss)
        {
            int L = 0, R = normala-1;
            while (R-L>1)
            {
                int mid = L+R>>1;
                if (normalni[mid].ff > s)
                    R = mid;
                else
                    L = mid;
            }
            if (normalni[R].ff <= s)
                beg = R;
            else
                beg = L;
           
            int cur = beg;
            if (normalni[cur].ff > s)
                continue;
            int mask = 0;
            for (int bit = 19; bit >= 0; bit--)
            {
                int cand = lifts[bit][cur];
                if (cand != -1 && normalni[cand].ss < f)
                {
                    cur = cand;
                    mask|=(1<<bit);
                }
            }
            if (nxt[cur] != -1)
            {
                cur = nxt[cur];
                mask++;
            }
            if (normalni[cur].ss < f)
                continue;
            mini = min(mask+2,mini);
        }

    }
    
    int lb = 0,rb = inf;
    for (int i = 0;i < n; i++)
        if (v[i].ff > v[i].ss)
        {
            lb = max(lb,v[i].ss);
            rb = min(rb,v[i].ff);
        }
    int used = 2;
    int maxright = lb;
    
    for (int i = 0; i < n; i++)
    {
        if (v[i].ff > maxright)
        {
            used++;
            if (i-1 < 0)
            {
                break;
            }
            maxright = v[i-1].ss;
            if (v[i].ff > maxright)
            {
                break;
            }
            if (maxright >= rb)
            {
                mini = min(used,mini);
            }
        }
    }
    if (mini == inf)
        return -1;
    else
        return mini;

}
 
signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int n,m;
    cin >> n >> m;
    vector<pii> v(n);
    for (int i = 0; i < n; i++)
        cin >> v[i].ff >> v[i].ss;
    cout << solve(n,m,v) << endl;
}

Compilation message (stderr)

Main.cpp: In function 'long long int solve(long long int, long long int, std::vector<std::pair<long long int, long long int> >)':
Main.cpp:91:24: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   91 |             int mid = l+r>>1;
      |                       ~^~
Main.cpp:129:28: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  129 |                 int mid = L+R>>1;
      |                           ~^~

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