Given a sequence of positive integers and another positive integer p. The sequence is said to be a perfect sequence if M≤m×p where M and m are the maximum and minimum numbers in the sequence, respectively.
Now given a sequence and a parameter p, you are supposed to find from the sequence as many numbers as possible to form a perfect subsequence.
Input Specification:
Each input file contains one test case. For each case, the first line contains two positive integers N and p, where N (≤) is the number of integers in the sequence, and p (≤) is the parameter. In the second line there are N positive integers, each is no greater than 1.
Output Specification:
For each test case, print in one line the maximum number of integers that can be chosen to form a perfect subsequence.
Sample Input:
10 8
2 3 20 4 5 1 6 7 8 9
Sample Output:
8
#include<bits/stdc++.h> using namespace std; const int maxn=100010; int n,p; int a[maxn]; int binarySearch(int i,long long x){ if(a[n-1]<=x){ return n; } int L=i+1,r=n-1,mid; while(L<r){ mid=(r+L)/2; if(a[mid]<=x){ L=mid+1; }else{ r=mid; } } return L; } int main(){ scanf("%d %d",&n,&p); for(int i=0;i<n;i++){ scanf("%d",&a[i]); } sort(a,a+n); int ans=1; for(int i=0;i<n;i++){ int j=binarySearch(i,(long long)a[i]*p); ans=max(ans,j-i); } printf("%d ",ans); return 0; }
扛不住了,要睡觉。。。