Submission #227233

#	Time	Username	Problem	Language	Result	Execution time	Memory
227233		stefanbalaz2	Port Facility (JOI17_port_facility)	C++14	22 / 100	2719 ms	407284 KiB

port_facility

/*



*/
#include <bits/stdc++.h>
using namespace std;
#define ff first
#define ss second
#define pb push_back
///#define ll long long
typedef pair<int,int> pii;
const int maxn=1e6+10;
int mod=1e9+7,e;
int levi[maxn],color[maxn],n,kolko,rez,grane;
pii niz[2*maxn];
vector<int>vect[maxn];
set<int>tree[(1<<22)+10];
void update(int x,int l,int r,int id,int val,int tip){
    if(tip)tree[x].insert(val);
    else tree[x].erase(val);
    if(l==r)return;
    int mid=(l+r)/2;
    if(id<=mid)update(x*2,l,mid,id,val,tip);
    else update(x*2+1,mid+1,r,id,val,tip);
}
void go(int x,int l,int r,int ll,int rr,int nd){

    if(l>=ll && r<=rr){
        for(set<int>::iterator it=tree[x].begin();it!=tree[x].end();it++){
            int id=(*it);

            vect[nd].pb(id);
            vect[id].pb(nd);

            grane++;

           /// printf("%d IDID\n",id);
        }
        return;
    }
    int mid=(l+r)/2;

    if(ll>mid)go(x*2+1,mid+1,r,ll,rr,nd);
    else if(rr<=mid)go(x*2,l,mid,ll,rr,nd);
    else{
        go(x*2,l,mid,ll,rr,nd);
        go(x*2+1,mid+1,r,ll,rr,nd);
    }
}
void dfs(int x,int col){

    color[x]=col;

    for(int i=0;i<vect[x].size();i++){
        int id=vect[x][i];
        if(color[id]==col)rez=0;
        else if(color[id]==-1)dfs(id,col^1);
    }
}
int main(){

    ///freopen("test.txt","r",stdin);

    scanf("%d",&n);
    int limit=10000000;
    if(n<=2000)limit=1e9;
    memset(color,-1,sizeof(color));
    for(int i=1;i<=n;i++){
        int a,b;
        scanf("%d %d",&a,&b);
        niz[a]={i,1};
        niz[b]={i,-1};
        levi[i]=a;
    }

    for(int i=1;i<=2*n;i++){

        if(niz[i].ss>0)update(1,1,2*n,i,niz[i].ff,1);
        else{

            int id=niz[i].ff;
            int lb=levi[id];
            update(1,1,2*n,lb,id,0);

            ///printf("%d AAAAA\n",id);

            go(1,1,2*n,lb,i,id);

            if(grane>limit){
                printf("0\n");
                return 0;
            }
        }

    }

    rez=1;
    for(int i=1;i<=n;i++){
        if(color[i]==-1){
            dfs(i,0);
            rez+=rez;
            if(rez>=mod)rez-=mod;
        }
    }


    printf("%d\n",rez);

	return 0;
}

Compilation message (stderr)

port_facility.cpp: In function 'void dfs(int, int)':
port_facility.cpp:55:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<vect[x].size();i++){
                 ~^~~~~~~~~~~~~~~
port_facility.cpp: In function 'int main()':
port_facility.cpp:65:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&n);
     ~~~~~^~~~~~~~~
port_facility.cpp:71:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d",&a,&b);
         ~~~~~^~~~~~~~~~~~~~~

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