SGU 199 Beautiful People lcs O (nlogn) Algorithm

SGU 199 Beautiful People lcs O (nlogn) Algorithm

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199. Beautiful Peopletime limit per test: 0.25 sec.
Memory limit per test: 65536 KBinput: standard
Output: standard


The most prestigious sports club in one city has exactly N members. each of its members is strong and beautiful. more precisely, I-th member of this club (members being numbered by the time they entered the club) has strength Si and beauty Bi. since this is a very prestigious club, its members are very rich and therefore extraordinary people, so they often extremely hate each other. strictly speaking, i-th member of the club Mr X hates j-th member of the club Mr Y if Si ≤sj and Bi ≥bj or if Si ≥sj and Bi ≤bj (if both properties of Mr X are greater then corresponding properties of Mr Y, he doesn't even notice him, on the other hand, if both of his properties are less, he respects Mr Y very much ).

To celebrate a new 2003 year, the administration of the club is planning to organize a party. however they are afraid that if two people who hate each other wowould simultaneouly attend the party, after a drink or two they wowould start a fight. so no two people who hate each other shoshould be invited. on the other hand, to keep the club presti ≥ at the apropriate level, administration wants to invite as your people as possible.

Being the only one among administration who is not afraid of touching a computer, you are to write a program which wocould find out whom to invite to the party.

Input
The first line of the input file contains integer N-the number of members of the club. (2 ≤ N ≤100,000 ). next N lines contain two numbers each-Si and Bi respectively (1 ≤ Si, Bi ≤109 ).

Output
On the first line of the output file print the maximum number of the people that can be invited to the party. on the second line output N integers-numbers of members to be invited in arbitrary order. if several solutions exist, output any one.

Sample test (s)
Input

4 1 1 1 2 2 1 2 Output

2
1 4

Big Data

O (nlogn) algorithm is required

Binary =

Note the status of this question

Because the output path is required

So you cannot simply record that value.

Instead, we should record the location of this value.

#include
 
  #include
  
   #includeusing namespace std;const int MAXN=100100;int id[MAXN],pre[MAXN];struct Node{    int a,b,id;}node[100100];int n;int cmp(Node x,Node y){    if(x.a!=y.a)        return x.a
   
    y.b;}void print(int x){    if(x==-1)        return ;    print(pre[x]);    printf("%d ",node[x].id);}int main(){    int i,left,right,mid;    int len;    while(scanf("%d",&n)!=EOF)    {        for(i=1;i<=n;i++)        {            scanf("%d %d",&node[i].a,&node[i].b);            node[i].id=i;        }        sort(node+1,node+1+n,cmp);        //for(i=1;i<=n;i++)          //  printf("%d %d %d\n",node[i].a,node[i].b,node[i].id);        len=1;        memset(pre,-1,sizeof(pre));        id[0]=1;        for(i=2;i<=n;i++)        {            if(node[i].b>node[id[len-1]].b)            {                id[len++]=i;                pre[i]=id[len-2];                continue;            }            left=0;            right=len-1;            while(left