Codeforces："North-East"

 1 #include <cstdio>
 2 #include <algorithm>
 3 #include <vector>
 4 #include <set>
 5 #define N 100005
 6 using namespace std;
 7 struct node{
 8     int x,y,id;
 9     friend bool operator<(node a,node b){
10         if(a.x==b.x)return a.y>b.y;
11         return a.x<b.x;
12     }
13 }a[N];
14 const int inf=1000005;
15 int n,dp[N],val[N],k,pos[N],maxy[N];
16 vector<int>v[N];
17 set<int>A,B;
18 void init(){
19     freopen("input.txt","r",stdin);
20     freopen("output.txt","w",stdout);
21 }
22 bool cmp(int x,int y){
23     return val[x]>val[y];
24 }
25 void output(){
26     printf("%d",A.size());
27     for(set<int>::iterator it=A.begin();it!=A.end();++it)
28         printf(" %d",*it);
29     printf("\n");
30     printf("%d",B.size());
31     for(set<int>::iterator it=B.begin();it!=B.end();++it)
32         printf(" %d",*it);
33     printf("\n");
34 }
35 int main(void){
36     init();
37     scanf("%d",&n);
38     for(int i=0;i<n;++i){
39         scanf("%d%d",&a[i].x,&a[i].y);
40         a[i].id=i+1;
41     }
42     sort(a,a+n);
43     for(int i=0;i<n;++i){
44         int v=a[i].y;
45         int t=lower_bound(dp,dp+k,v)-dp;
46         dp[t]=v;
47         val[a[i].id]=a[i].y;
48         pos[a[i].id]=t;
49         if(t==k)k++;
50     }
51     for(int i=0;i<k;++i)
52         maxy[i]=-inf;
53     maxy[k]=inf;
54     for(int i=n-1;i>=0;--i){
55         int id=a[i].id;
56         int p=pos[id];
57         if(val[id]<maxy[p+1]){
58             A.insert(id);
59             maxy[p]=max(maxy[p],val[id]);
60             v[p].push_back(id);
61         }
62     }
63     for(int i=0;i<k;++i)
64         if((int)v[i].size()==1)
65             B.insert(v[i][0]);
66     output();
67 }