Submission #1108900

#	Time	Username	Problem	Language	Result	Execution time	Memory
1108900		vjudge1	Port Facility (JOI17_port_facility)	C++17	0 / 100	33 ms	193104 KiB

port_facility

#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define for1(i,j,k) for(int i=j;i<=k;i++)
#define for2(i,j,k) for(int i=j;i>=k;i--)
#define for3(i,j,k,l) for(int i=j;i<=k;i+=l)
#define int long long
#define all(x) x.begin(),x.end()

typedef long long ll;
typedef pair<int,int> pii;

const ll maxn=2e6+5;
const ll offset=2e5;
const ll inf=1e18;
const int base=550;
const ll mod=1e9+7;
int n,m;
pii a[maxn];
int par[maxn];
bool col[maxn];
vector<int> st[maxn*4];
int pt[maxn*4];
pii Find(int u)
{
    int c=0;
    while (par[u]>0)
    {
        c^=col[u];
        u=par[u];
    }
    c^=col[u];
    return {u,c};
}
bool Union(int u,int v,bool same)
{
//    cerr<< "Merge "<<u<<' '<<v<<' '<<same<<'\n';
    pii x=Find(u),y=Find(v);
    u=x.fi;
    v=y.fi;
    int cu=x.se,cv=y.se;
    if (u==v) return same^(cu!=cv);
    par[u]+=par[v];
    par[v]=u;
    col[v]=same^1;
    return 1;
}

void Update(int u,int val,int id=1,int l=1,int r=2*n)
{
    st[id].pb(val);
    if (l==r) return;
    int mid=l+r>>1;
    if (u<=mid) Update(u,val,id*2,l,mid);
    else Update(u,val,id*2+1,mid+1,r);
}
void Edge(int u,int v,int val,int id=1,int l=1,int r=2*n)
{
    if (st[id].empty()||u>r || v<l) return;
    if (u<=l && r<=v)
    {
        while (pt[id]<st[id].size())
        {
            if (pt[id]!=0) if (!Union(st[id][pt[id]],st[id][pt[id]-1],1))
            {
                cout << "0";
                exit(0);
            }
            pt[id]++;
        }
        if (!Union(val,st[id].back(),0))
        {
            cout << "0";
            exit(0);
        }
        return;
    }
    int mid=l+r>>1;
    Edge(u,v,val,id*2,l,mid);
    Edge(u,v,val,id*2+1,mid+1,r);
}

void sol()
{
    cin >> n;
    for1(i,1,n)
    {
        par[i]=-1;
        cin >> a[i].fi>> a[i].se;
    }
    sort(a+1,a+1+n,[](pii x,pii y)
         {
            return x.se>y.se;
         });
    for1(i,1,n)
    {
//        cerr<<i<<' '<<a[i].fi<<' '<<a[i].se<<'\n';
        Edge(a[i].fi,a[i].se,i);
        Update(a[i].fi,i);
    }
    int res=1;
    for1(i,1,n)
    {
        if (par[i]<0) res=res*2%mod;
    }
    cout << res;
}
int32_t main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    #define task "acll"
//    freopen(task".inp","r",stdin);
//    freopen(task".out","w",stdout);

    int t=1;//cin >> t;
    while (t--) {
        sol();
    }
}

/*
10 2 0
2 1 4 3 5 6 8 7 10 9
1
2 5 8
6 1 12
2 1 3 4 5 6
6
1 1 4
1 2 6
2 1 2
2 1 3
2 1 5
2 1 6





*/

Compilation message (stderr)

port_facility.cpp: In function 'void Update(long long int, long long int, long long int, long long int, long long int)':
port_facility.cpp:55:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   55 |     int mid=l+r>>1;
      |             ~^~
port_facility.cpp: In function 'void Edge(long long int, long long int, long long int, long long int, long long int, long long int)':
port_facility.cpp:64:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   64 |         while (pt[id]<st[id].size())
      |                ~~~~~~^~~~~~~~~~~~~~
port_facility.cpp:80:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   80 |     int mid=l+r>>1;
      |             ~^~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 12
• Subtask 3: 0 / 56
• Subtask 4: 0 / 22