Submission #888993

#	Time	Username	Problem	Language	Result	Execution time	Memory
888993		ducngo	Passport (JOI23_passport)	C++17	6 / 100	27 ms	8540 KiB

passport

#include <bits/stdc++.h>
#define getbit(i, j) ((i >> j) & 1)
#define maxn 200005
#define name "Passport"
using namespace std;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

long long GetRandom(long long l, long long r)
{
    return uniform_int_distribution<long long> (l, r)(rng);
}

int n,q,r[maxn];
int dpl[2505][2505],dpr[2505][2505];
pair<int,int> a[maxn];
int f[2505][2505],xd[2505][2505];

int tinh(int d,int c)
{
    if(d>c) return 1e9;
    if(d==1&&c==n) return 0;
    if(xd[d][c]==1) return f[d][c];

    xd[d][c]=1;
    int val=1e9;
    if(d==c) val=min(val,tinh(a[d].first,a[d].second)+1);
    else
    {
        int u=dpl[d][c];
        val=min(val,tinh(u,c)+1);
        u=dpr[d][c];
        val=min(val,tinh(d,u)+1);
        val=min({val,tinh(d+1,c),tinh(d,c-1)});
    }
    f[d][c]=val;
    return f[d][c];
}

void sub1()
{
    int vt=1,sl=0;
    while(vt<n)
    {
        int luu=vt;
//        cout<<vt<<' '<<dpr[1][vt]<<'\n';
        vt=r[vt];
        sl++;
        if(luu==vt) break;
    }
    if(vt!=n) cout<<-1<<'\n';
    else cout<<sl<<'\n';
    exit(0);
}

void sub()
{
    r[1]=a[1].second;
    for(int i=2; i<=n; i++) r[i]=max(r[i-1],a[i].second);
    int x;
    cin >> x;
    sub1();
    exit(0);
}

void sub3()
{
    for(int i=1; i<=n; i++)
    {
        dpl[i][i]=a[i].first;
        dpr[i][i]=a[i].second;
        for(int j=i+1; j<=n; j++)
        {
            dpl[i][j]=min(dpl[i][j-1],a[j].first);
            dpr[i][j]=max(dpr[i][j-1],a[j].second);
        }
    }
    for(int i=1; i<=n; i++)
    {
        for(int j=1; j<=n; j++) f[i][j]=1e9;
    }

    for(int i=1; i<=q; i++)
    {
        int x;
        cin >> x;
        int val=tinh(x,x);
        if(val>n) cout<<-1<<'\n';
        else cout<<val<<'\n';
    }
    exit(0);
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    if(fopen(name".inp","r"))
    {
        freopen(name".inp","r",stdin);
        freopen(name".out","w",stdout);
    }
    cin >> n;
    for(int i=1; i<=n; i++)
    {
        cin >> a[i].first >> a[i].second;
    }
    cin >> q;
    if(n>2500&&q==1) sub();
    if(n<=2500)sub3();
}

Compilation message (stderr)

passport.cpp: In function 'int main()':
passport.cpp:101:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  101 |         freopen(name".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
passport.cpp:102:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  102 |         freopen(name".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 6 / 6
• Subtask 2: 0 / 16
• Subtask 3: 0 / 24
• Subtask 4: 0 / 8
• Subtask 5: 0 / 46